Supplemental fuel system for compression-ignition engine

ABSTRACT

A supplemental fuel system includes a supplemental fuel tank, a first pressure regulator, a second pressure regulator, and a nozzle. The supplemental fuel tank is configured to store a supplemental fuel at a first pressure. The first pressure regulator is configured to reduce the first pressure of the supplemental fuel received from the supplemental fuel tank to a second pressure. The second pressure regulator is configured to reduce the second pressure of the supplemental fuel received from the first pressure regulator to a third pressure. The nozzle is configured to be positioned (i) downstream of the second pressure regulator and (ii) within a conduit of an air supply system for the compression-ignition engine. The nozzle is configured to receive a flow of the supplemental fuel and provide the supplemental fuel to air flowing though the conduit.

CROSS-REFERENCE TO RELATED PATENT APPLICATIONS

This application claims the benefit of and priority to (a) U.S.Provisional Patent Application No. 62/497,357, filed Sep. 1, 2021, (b)U.S. Provisional Patent Application No. 63/324,224, filed Mar. 28, 2022,(c) U.S. Provisional Patent Application No. 63/324,230, filed Mar. 28,2022, (d) U.S. Provisional Patent Application No. 63/324,231, filed Mar.28, 2022, (e) U.S. Provisional Patent Application No. 63/324,306, filedMar. 28, 2022, (f) U.S. Provisional Patent Application No. 63/324,411,filed Mar. 28, 2022, (g) U.S. Provisional Patent Application No.63/324,420, filed Mar. 28, 2022, and (h) U.S. Provisional PatentApplication No. 63/324,447, filed Mar. 28, 2022, all of which areincorporated herein by reference in their entireties.

BACKGROUND

Compression-ignition internal combustion engines (e.g., diesel engines)typically include a fuel tank fluidly connected to a fuel injector thatis configured to supply (e.g., spray) a combustible fuel (e.g., diesel)from the fuel tank into a charge of heated and compressed air within anengine cylinder. The high temperature and high pressure of the charge ofheated and compressed air within the engine cylinder causes the fuelinjected therein to ignite and expand, which drives subsequent stages ofthe engine cycle (e.g., the power stroke). Compression-ignition internalcombustion engines are often compatible with a variety of fuels due tothe high engine temperatures achieved within the engine cylinder(s)during operation. Accordingly, a large number and variety of fuelsand/or combinations of fuels may be suitable for use within acompression-ignition internal combustion engine.

For example, natural gas and other gaseous fuels have been used as adedicated fuel, or blended fuel supplement in diesel engines fordecades. There are existing “conversion kits” on the market today thatdeliver natural gas, propane, or other supplemental fuel to dieselengines. However, such conversion kits available today are designed fora specific engine or vehicle, rendering the conversion kits useless forengines or vehicles that they were not specifically designed tosupplement. Such engine or vehicle specific kits lead to unfamiliarityby the installing technicians, which can make the kits complex toinstall, difficult to properly tune, and can lead to engine damage.

SUMMARY

One embodiment relates to a supplemental fuel system for a machinehaving a compression-ignition engine. The supplemental fuel systemincludes a fuel mixer. The fuel mixer includes a nozzle and a stem. Thenozzle is configured to be positioned within a conduit of an air supplysystem for the compression-ignition engine. The nozzle has a bodydefining a first inlet positioned at a first nozzle end thereof, anoutlet positioned at an opposing second nozzle end thereof, a secondinlet positioned between the first nozzle end and the opposing secondnozzle end, and a nozzle passage extending from the first nozzle end tothe opposing second nozzle end that is configured to receive air flowingthrough the conduit. The stem has a first stem end and a second stemend. The first stem end interfaces with the second inlet. The stem isconfigured to extend through a wall of the conduit such that the secondstem end is positioned outside of the conduit. The stem is configured toreceive a supplemental fuel from a supplemental fuel tank and providethe supplemental fuel to the nozzle passage of the nozzle through thesecond inlet.

Another embodiment relates to a supplemental fuel system for a machinehaving a compression-ignition engine. The supplemental fuel systemincludes a nozzle configured to be positioned within a conduit of an airsupply system for the compression-ignition engine. The nozzle has afirst inlet positioned at a first end thereof, an outlet positioned atan opposing second end thereof, a nozzle passage extending from thefirst end to the opposing second end, and a second inlet. The nozzlepassage is configured to receive air flowing through the conduit. Thenozzle passage has a non-uniform profile with a first transition point,a second transition point, an inlet taper extending from the first endto the first transition point, a mixing chamber positioned between thefirst transition point and the second transition point, and an outlettaper extending from the second transition point to the opposing secondend. The second inlet is positioned along the mixing chamber closer tothe second transition point than the first transition point. The inlettaper has a first longitudinal length and the outlet taper has a secondlongitudinal length. A ratio of the second longitudinal length to thefirst longitudinal length is about 3:1. The nozzle is configured togenerate a vacuum signal at the second inlet as the air flowing throughthe conduit flows through the nozzle passage to draw a flow ofsupplemental fuel from a supplemental fuel source into the mixingchamber.

Another embodiment relates to a supplemental fuel system for a machinehaving a compression-ignition engine. The supplemental fuel systemincludes a nozzle, a stem, and a valve assembly. The nozzle isconfigured to be positioned within a conduit of an air supply system forthe compression-ignition engine. The nozzle has a first inlet positionedat a first nozzle end thereof, an outlet positioned at an opposingsecond nozzle end thereof, a nozzle passage extending from the firstnozzle end to the opposing second nozzle end, and a second inlet. Thenozzle passage is configured to receive air flowing through the conduit.The nozzle passage has a non-uniform profile with a first transitionpoint, a second transition point, an inlet taper extending from thefirst nozzle end to the first transition point, a mixing chamberpositioned between the first transition point and the second transitionpoint, and an outlet taper extending from the second transition point tothe opposing second nozzle end. The inlet taper is different than theoutlet taper. The second inlet is positioned along the mixing chamber.The stem has a first stem end and a second stem end. The first stem endinterfaces with the second inlet. The stem is configured to extendthrough a wall of the conduit such that the second stem end ispositioned outside of the conduit. The valve assembly includes a valvebody and an adjuster. The valve body defines a valve body inletconfigured to receive a supplemental fuel from a supplemental fuelsource and a valve body outlet interfacing with the second stem end ofthe stem. The adjuster is positioned to facilitate selectivelyrestricting an amount of flow of the supplemental fuel through the valvebody outlet to the stem and the nozzle. The nozzle is configured togenerate a vacuum signal at the second inlet as the air flowing throughthe conduit flows through the nozzle passage to draw a flow of thesupplemental fuel through the valve assembly and the stem into themixing chamber.

Another embodiment relates to a supplemental fuel system for a machinehaving a compression-ignition engine. The supplemental fuel systemincludes a supplemental fuel tank, a first pressure regulator, a secondpressure regulator, a nozzle, an electronic lock off valve, and acontroller. The supplemental fuel tank is configured to store asupplemental fuel at a first pressure. The supplemental fuel isconfigured to supplement a primary fuel used by the compression-ignitionengine. The first pressure regulator is configured to be positioneddownstream of the supplemental fuel tank. The first pressure regulatoris configured to reduce the first pressure of the supplemental fuelreceived from the supplemental fuel tank to a second pressure. Thesecond pressure regulator is configured to be positioned downstream ofthe first pressure regulator. The second pressure regulator isconfigured to reduce the second pressure of the supplemental fuelreceived from the first pressure regulator to a third pressure. Thenozzle is configured to be positioned (i) downstream of the secondpressure regulator and (ii) within a conduit of an air supply system forthe compression-ignition engine. The nozzle is configured to receive aflow of the supplemental fuel and provide the supplemental fuel to airflowing though the conduit. The electronic lock off valve is configuredto be positioned between the supplemental fuel tank and the nozzle. Thecontroller is configured to control the electronic lock off valve toselectively disengage the supplemental fuel system and prevent thesupplemental fuel from being provided to the air flowing through theconduit.

Another embodiment relates to a supplemental fuel system for a machinehaving a compression-ignition engine. The supplemental fuel systemincludes a supplemental fuel tank, a first pressure regulator, a secondpressure regulator, and a fuel mixer. The supplemental fuel tank isconfigured to store a supplemental fuel at a first pressure. Thesupplemental fuel is configured to supplement a primary fuel used by thecompression-ignition engine. The first pressure regulator is configuredto be positioned downstream of the supplemental fuel tank. The firstpressure regulator is configured to reduce the first pressure of thesupplemental fuel received from the supplemental fuel tank to a secondpressure. The second pressure regulator is configured to be positioneddownstream of the first pressure regulator. The second pressureregulator id configured to reduce the second pressure of thesupplemental fuel received from the first pressure regulator to a thirdpressure. The fuel mixer is configured to be positioned downstream ofthe second pressure regulator. The fuel mixer includes a valve body, anadjuster, a stem, and a Venturi nozzle. The valve body defines a valvebody inlet and a valve body outlet. The valve body inlet is configuredto receive a flow of the supplemental fuel from the second pressureregulator. The adjuster is positioned to facilitate selectivelyrestricting an amount of the flow of the supplemental fuel through thevalve body outlet. The stem has a first stem end and a second stem end.The first stem end interfaces with the valve body outlet. The stem isconfigured to extend through a wall of a conduit of an air supply systemfor the compression-ignition engine such that the second stem end ispositioned inside of the conduit. The Venturi nozzle interfaces with thesecond stem end of the stem and is configured to be positioned withinthe conduit. The Venturi nozzle is configured to receive at least aportion of air flowing through the conduit and generate a vacuum signalat the second pressure regulator as the at least the portion of airflows through the Venturi nozzle. The Venturi nozzle is configured to(i) receive the flow of the supplemental fuel from the second pressureregulator in response to and based on the vacuum signal and (ii) mix theflow of the supplemental fuel with the at least the portion of air.

Another embodiment relates to a supplemental fuel system for a machinehaving a compression-ignition engine. The supplemental fuel systemincludes a supplemental fuel tank, a first pressure regulator, a secondpressure regulator, a fuel mixer, an electronic lock off valve, andcontroller. The supplemental fuel tank I s configured to store asupplemental fuel at a first pressure. The supplemental fuel isconfigured to supplement a primary fuel used by the compression-ignitionengine. The first pressure regulator is configured to be positioneddownstream of the supplemental fuel tank. The first pressure regulatoris configured to reduce the first pressure of the supplemental fuelreceived from the supplemental fuel tank to a second pressure. Thesecond pressure regulator is configured to be positioned downstream ofthe first pressure regulator. The second pressure regulator isconfigured to reduce the second pressure of the supplemental fuelreceived from the first pressure regulator to a third pressure. The fuelmixer is configured to be positioned downstream of the second pressureregulator. The fuel mixer includes a valve body, an adjuster, a stem,and a Venturi nozzle. The valve body defines a valve body inlet and avalve body outlet. The valve body inlet is configured to receive a flowof the supplemental fuel from the second pressure regulator. Theadjuster is positioned to facilitate selectively restricting an amountof the flow of the supplemental fuel through the valve body outlet. Thestem has a first stem end and a second stem end. The first stem endinterfaces with the valve body outlet. The stem is configured to extendthrough a wall of a conduit of an air supply system for thecompression-ignition engine such that the second stem end is positionedinside of the conduit. The Venturi nozzle interfaces with the secondstem end of the stem and is configured to be positioned within theconduit. The Venturi nozzle is configured to receive at least a portionof air flowing through the conduit and generate a vacuum signal at thesecond pressure regulator as the at least the portion of air flowsthrough the Venturi nozzle. The Venturi nozzle is configured to (i)receive the flow of the supplemental fuel from the second pressureregulator in response to and based on the vacuum signal and (ii) mix theflow of the supplemental fuel with the at least the portion of air. Theelectronic lock off valve is configured to be positioned between thesupplemental fuel tank and the fuel mixer. The controller is configuredto control the electronic lock off valve to selectively prevent thesupplemental fuel from being provided to the fuel mixer.

Another embodiment relates to a supplemental fuel system for a machinehaving a compression-ignition engine. The supplemental fuel systemincludes a fuel mixer. The fuel mixer includes a nozzle and a stem. Thenozzle is configured to be positioned within a conduit of an air supplysystem for the compression-ignition engine. The nozzle has a bodydefining a first inlet, an outlet, a nozzle passage extending from thefirst inlet to the outlet, and a second inlet positioned between thefirst inlet and the outlet. The body has a first cross-sectionaldimension that is configured to be less than a second cross-sectionaldimension of the conduit such that (i) a first portion of air flowingthrough the conduit flows through the nozzle passage and (ii) a secondportion of the air flowing through the conduit flows around the nozzle.The stem has a first stem end and a second stem end. The first stem endinterfaces with the second inlet. The stem is configured to extendthrough a wall of the conduit such that the second stem end ispositioned outside of the conduit. The stem is configured to receive asupplemental fuel from a supplemental fuel source and provide thesupplemental fuel through the second inlet of the nozzle to the firstportion of the air flowing through the nozzle passage of the nozzle.

Another embodiment relates to a supplemental fuel system for a machinehaving a compression-ignition engine. The supplemental fuel systemincludes a nozzle. The nozzle is configured to be positioned within aconduit of an air supply system for the compression-ignition engine. Thenozzle has a passage with an inlet, a first transition point, a secondtransition point, an outlet, an inlet taper extending from the inlet tothe first transition point, a mixing chamber positioned between thefirst transition point and the second transition point, and an outlettaper extending from the second transition point to the outlet. Thenozzle has a second inlet positioned along the mixing chamber closer tothe second transition point than the first transition point. The nozzlehas a first cross-sectional dimension that is configured to be less thana second cross-sectional dimension of the conduit such that (i) a firstportion of air flowing through the conduit flows through the passage and(ii) a second portion of the air flowing through the conduit flowsaround the nozzle. The inlet taper has a first longitudinal length andthe outlet taper has a second longitudinal length. A ratio of the secondlongitudinal length to the first longitudinal length is about 3:1. Thenozzle is configured to generate a vacuum signal at the second inlet asthe first portion of the air flows through the passage to draw a flow ofa supplemental fuel from a supplemental fuel source into the mixingchamber.

Another embodiment relates to a supplemental fuel system for a machinehaving a compression-ignition engine. The supplemental fuel systemincludes a nozzle, a stem, a valve body, and an adjuster. The nozzle isconfigured to be positioned within a conduit of an air supply system forthe compression-ignition engine. The nozzle has a passage with an inlet,a first transition point, a second transition point, an outlet, an inlettaper extending from the inlet to the first transition point, a mixingchamber positioned between the first transition point and the secondtransition point, and an outlet taper extending from the secondtransition point to the outlet. The nozzle has a second inlet positionedalong the mixing chamber closer to the second transition point than thefirst transition point. The nozzle has an outer diameter of about 3inches, the mixing chamber has a chamber diameter of about 2 inches, thenozzle has a nozzle length of about 4 inches, the inlet taper has aninlet length of about 0.5 inches, the mixing chamber has a chamberlength of about 2 inches, and the outlet taper has an outlet length ofabout 1.5 inches. The outer diameter is configured to be less than across-sectional dimension of the conduit such that (i) a first portionof air flowing through the conduit flows through the passage and (ii) asecond portion of the air flowing through the conduit flows around thenozzle. The stem has a first stem end and a second stem end. The firststem end interfaces with the second inlet. The stem is configured toextend through a wall of the conduit such that the second stem end ispositioned outside of the conduit. The valve body defines a valve bodyinlet configured to receive a supplemental fuel from a supplemental fuelsource and a valve body outlet interfacing with the second stem end ofthe stem. The adjuster is positioned to facilitate selectivelyrestricting an amount of the supplemental fuel through the valve bodyoutlet to the stem and the nozzle. The nozzle is configured to generatea vacuum signal at the second inlet as the first portion of the airflows through the passage to draw a flow of the supplemental fuel intothe mixing chamber.

Another embodiment relates to a supplemental fuel system for a machinehaving a compression-ignition engine. The supplemental fuel systemincludes an air intake tube. The air intake tube has a first endconfigured to interface with an air cleaner of an air supply system thatprovides air to the compression-ignition engine, a second end configuredto interface with a compressor of a turbocharger of the air supplysystem, and a sidewall extending between the first end and the secondend. The sidewall includes a fuel interface configured to facilitateproviding a supplemental fuel into the air intake tube to mix with theair upstream of the compressor of the turbocharger.

Another embodiment relates to a supplemental fuel system for a machinehaving a compression-ignition engine. The supplemental fuel systemincludes an air intake tube, a stem, and a nozzle. The air intake tubehas a first end configured to interface with an air cleaner of an airsupply system that provides air to the compression-ignition engine, asecond end configured to interface with a compressor of a turbochargerof the air supply system, and a sidewall extending between the first endand the second end. The stem extends through the sidewall between thefirst end and the second end. The stem is configured to couple to asupplemental fuel source. The nozzle is positioned within the air intaketube. The nozzle defines a nozzle passage that has an air inlet, anoutlet, a first transition point, a second transition point, an inlettaper extending from the air inlet to the first transition point, amixing chamber positioned between the first transition point and thesecond transition point, an outlet taper extending from the secondtransition point to the outlet, and a fuel inlet positioned along themixing chamber and that interfaces with the stem. The nozzle has anouter diameter of about 3 inches, the mixing chamber has a chamberdiameter of about 2 inches, the nozzle has a nozzle length of about 4inches, the inlet taper has an inlet length of about 0.5 inches, themixing chamber has a chamber length of about 2 inches, and the outlettaper has an outlet length of about 1.5 inches. The outer diameter isless than a cross-sectional dimension of the air intake tube such that(i) a first portion of the air flowing through the air intake tube flowsthrough the nozzle passage and (ii) a second portion of the air flowingthrough the air intake tube flows around the nozzle. The nozzle isconfigured to generate a vacuum signal at the fuel inlet as the firstportion of the air flows through the nozzle passage to facilitatedrawing a supplemental fuel from the supplemental fuel source into theair intake tube to mix with the air upstream of the compressor of theturbocharger.

Another embodiment relates to a supplemental fuel system for a machinehaving a compression-ignition engine. The supplemental fuel systemincludes an air intake tube, a stem, and a nozzle. The air intake tubehas a first end configured to interface with an air cleaner of an airsupply system that provides air to the compression-ignition engine, asecond end configured to interface with a compressor of a turbochargerof the air supply system, and a sidewall extending between the first endand the second end. The stem extends through the sidewall between thefirst end and the second end. The stem is configured to couple to asupplemental fuel source. The nozzle is positioned within the air intaketube. The nozzle defines an air inlet, a fuel inlet that interfaces withthe stem, and an outlet. The nozzle is configured to generate a vacuumsignal at the fuel inlet as the air flows through the nozzle tofacilitate drawing a supplemental fuel from the supplemental fuel sourceinto the air intake tube to mix with the air upstream of the compressorof the turbocharger.

Another embodiment relates to a supplemental fuel system for a machinehaving a compression-ignition engine. The supplemental fuel systemincludes a supplemental fuel tank, an electronic lock off valve, avoltage sensor, and a controller. The supplemental fuel tank isconfigured to store a supplemental fuel. The supplemental fuel isconfigured to supplement a primary fuel used by the compression-ignitionengine. The electronic lock off valve is configured to be positionedbetween the supplemental fuel tank and an air supply system for thecompression-ignition engine. The voltage sensor is configured to acquirevoltage data from a power supply of the machine indicative of a voltageof the power supply. The power supply is configured to receive powerfrom an alternator driven by the compression-ignition engine. Thecontroller is configured to monitor the voltage of the power supplybased on the voltage data acquired by the voltage sensor, compare thevoltage to a voltage threshold, and control the electronic lock offvalve such that the electronic lock off valve is (i) closed to preventthe supplemental fuel from being provided to the air supply system inresponse to the voltage being less than the voltage threshold and (ii)open or openable to permit the supplemental fuel to be provided to theair supply system in response to the voltage being greater than thevoltage threshold.

Another embodiment relates to a supplemental fuel system for a machinehaving a compression-ignition engine. The supplemental fuel systemincludes an electronic lock off valve, voltage sensor, and a controller.The electronic lock off valve is configured to be positioned between asupplemental fuel tank and an air supply system for thecompression-ignition engine. The supplemental fuel tank is configured tostore a supplemental fuel that supplements a primary fuel used by thecompression-ignition engine. The voltage sensor is configured to acquirevoltage data from a power supply of the machine indicative of a voltageof the power supply. The power supply is configured to receive powerfrom an alternator driven by the compression-ignition engine. Thecontroller is configured to monitor the voltage of the power supplybased on the voltage data acquired by the voltage sensor and control theelectronic lock off valve such that the electronic lock off valve isclosed to prevent the supplemental fuel from being provided to the airsupply system in response to the voltage being less than a voltagethreshold.

Another embodiment relates to a supplemental fuel system for a machinehaving a compression-ignition engine. The supplemental fuel systemincludes a supplemental fuel tank, a first pressure regulator, a secondpressure regulator, a fuel mixer, an electronic lock off valve, avoltage sensor, and a controller. The supplemental fuel tank isconfigured to store a supplemental fuel. The supplemental fuel isconfigured to supplement a primary fuel used by the compression-ignitionengine. The first pressure regulator is configured to be positioneddownstream of the supplemental fuel tank. The first pressure regulatoris configured to reduce a pressure of the supplemental fuel receivedfrom the supplemental fuel tank from a first pressure to a secondpressure. The second pressure regulator is configured to be positioneddownstream of the first pressure regulator. The second pressureregulator is configured to reduce the pressure of the supplemental fuelreceived from the first pressure regulator from the second pressure to athird pressure. The fuel mixer is configured to be positioned downstreamof the second pressure regulator. The fuel mixer includes a nozzle, astem, and a valve assembly. The nozzle is configured to be positionedwithin a conduit of an air supply system for the compression-ignitionengine. The nozzle is configured to receive a flow of the supplementalfuel and provide the supplemental fuel to air flowing through theconduit. The stem is configured to extend through a wall of the conduitand interface with the nozzle. The valve assembly includes a valve bodyand an adjuster. The valve body defines a valve body inlet configured toreceive the flow of the supplemental fuel from the second pressureregulator and a valve body outlet interfacing with the stem. Theadjuster is positioned to facilitate selectively restricting an amountof the flow of the supplemental fuel through the valve body outlet andprovided to the stem and the nozzle. The electronic lock off valve isconfigured to be positioned between the supplemental fuel tank and thefuel mixer. The voltage sensor is configured to acquire voltage datafrom a power supply of the machine indicative of a voltage of the powersupply. The power supply is configured to receive power from analternator driven by the compression-ignition engine. The controller isconfigured to monitor the voltage of the power supply based on thevoltage data acquired by the voltage sensor, compare the voltage to avoltage threshold, and control the electronic lock off valve such thatthe electronic lock off valve is (i) closed to prevent the supplementalfuel from being provided to the air supply system in response to thevoltage being less than the voltage threshold and (ii) open or openableto permit the supplemental fuel to be provided to the air supply systemin response to the voltage being greater than the voltage threshold.

Another embodiment relates to a supplemental fuel system for a machinehaving a compression-ignition engine. The supplemental fuel systemincludes a supplemental fuel tank, an electronic lock off valve, atemperature sensor, and a controller. The supplemental fuel tank isconfigured to store a supplemental fuel. The supplemental fuel isconfigured to supplement a primary fuel used by the compression-ignitionengine. The electronic lock off valve is configured to be positionedbetween the supplemental fuel tank and an air supply system for thecompression-ignition engine. The temperature sensor is configured toacquire temperature data regarding a temperature of exhaust gas outputby the compression-ignition engine. The controller is configured tomonitor the temperature of the exhaust gas based on the temperature dataacquired by the temperature sensor, compare the temperature to atemperature threshold, and control the electronic lock off valve suchthat the electronic lock off valve is (i) closed to prevent thesupplemental fuel from being provided to the air supply system inresponse to the temperature being greater than the temperature thresholdand (ii) open or openable to permit the supplemental fuel to be providedto the air supply system in response to the temperature being less thanthe temperature threshold.

Another embodiment relates to a supplemental fuel system for a machinehaving a compression-ignition engine. The supplemental fuel systemincludes an electronic lock off valve, a temperature sensor, and acontroller. The electronic lock off valve is configured to be positionedbetween a supplemental fuel tank and an air supply system for thecompression-ignition engine. The supplemental fuel tank is configured tostore a supplemental fuel that supplements a primary fuel used by thecompression-ignition engine. The temperature sensor is configured toacquire temperature data regarding a temperature of exhaust gas outputby the compression-ignition engine. The controller is configured tomonitor the temperature of the exhaust gas based on the temperature dataacquired by the temperature sensor and control the electronic lock offvalve such that the electronic lock off valve is closed to prevent thesupplemental fuel from being provided to the air supply system inresponse to the temperature being greater than a temperature threshold.

Another embodiment relates to a supplemental fuel system for a machinehaving a compression-ignition engine. The supplemental fuel systemincludes a supplemental fuel tank, a first pressure regulator, a secondpressure regulator, a fuel mixer, an electronic lock off valve, atemperature sensor, and a controller. The supplemental fuel tank isconfigured to store a supplemental fuel. The supplemental fuel isconfigured to supplement a primary fuel used by the compression-ignitionengine. The first pressure regulator is configured to be positioneddownstream of the supplemental fuel tank. The first pressure regulatoris configured to reduce a pressure of the supplemental fuel receivedfrom the supplemental fuel tank from a first pressure to a secondpressure. The second pressure regulator is configured to be positioneddownstream of the first pressure regulator. The second pressureregulator is configured to reduce the pressure of the supplemental fuelreceived from the first pressure regulator from the second pressure to athird pressure. The fuel mixer is configured to be positioned downstreamof the second pressure regulator. The fuel mixer includes a nozzle, astem, and a valve assembly. The nozzle is configured to be positionedwithin a conduit of an air supply system for the compression-ignitionengine. The nozzle is configured to receive a flow of the supplementalfuel and provide the supplemental fuel to air flowing through theconduit. The stem is configured to extend through a wall of the conduitand interface with the nozzle. The valve assembly includes a valve bodyand an adjuster. The valve body defines a valve body inlet configured toreceive the flow of the supplemental fuel from the second pressureregulator and a valve body outlet interfacing with the stem. Theadjuster is positioned to facilitate selectively restricting an amountof the flow of the supplemental fuel through the valve body outlet andprovided to the stem and the nozzle. The electronic lock off valve isconfigured to be positioned between the supplemental fuel tank and thefuel mixer. The temperature sensor is configured to acquire temperaturedata regarding a temperature of exhaust gas output by thecompression-ignition engine. The controller is configured to monitor thetemperature of the exhaust gas based on the temperature data acquired bythe temperature sensor, compare the temperature to a temperaturethreshold, and control the electronic lock off valve such that theelectronic lock off valve is (i) closed to prevent the supplemental fuelfrom being provided to the air supply system in response to thetemperature being greater than the temperature threshold and (ii) openor openable to permit the supplemental fuel to be provided to the airsupply system in response to the temperature being less than thetemperature threshold.

Another embodiment relates to a supplemental fuel system for a machinehaving a compression-ignition engine. The supplemental fuel systemincludes a supplemental fuel tank, an electronic lock off valve, atemperature sensor, and a controller. The supplemental fuel tank isconfigured to store a supplemental fuel. The supplemental fuel isconfigured to supplement a primary fuel used by the compression-ignitionengine. The electronic lock off valve is configured to be positionedbetween the supplemental fuel tank and an air supply system for thecompression-ignition engine. The temperature sensor is configured toacquire temperature data regarding a temperature of thecompression-ignition engine. The controller is configured to monitor thetemperature of the compression-ignition engine based on the temperaturedata acquired by the temperature sensor, compare the temperature to atemperature threshold, and control the electronic lock off valve suchthat the electronic lock off valve is (i) closed to prevent thesupplemental fuel from being provided to the air supply system inresponse to the temperature being less than the temperature thresholdand (ii) open or openable to permit the supplemental fuel to be providedto the air supply system in response to the temperature being greaterthan the temperature threshold.

Another embodiment relates to a supplemental fuel system for a machinehaving a compression-ignition engine. The supplemental fuel systemincludes an electronic lock off valve, a temperature sensor, and acontroller. The electronic lock off valve is configured to be positionedbetween a supplemental fuel tank and an air supply system for thecompression-ignition engine. The supplemental fuel tank is configured tostore a supplemental fuel that supplements a primary fuel used by thecompression-ignition engine. The temperature sensor is configured toacquire temperature data regarding a temperature of thecompression-ignition engine. The controller is configured to monitor thetemperature of the compression-ignition engine based on the temperaturedata acquired by the temperature sensor and control the electronic lockoff valve such that the electronic lock off valve is closed to preventthe supplemental fuel from being provided to the air supply system inresponse to the temperature being less than a temperature threshold.

Still another embodiment relates to a supplemental fuel system for amachine having a compression-ignition engine. The supplemental fuelsystem includes a supplemental fuel tank, a first pressure regulator, asecond pressure regulator, a fuel mixer, an electronic lock off valve, atemperature sensor, and a controller. The supplemental fuel tank isconfigured to store a supplemental fuel. The supplemental fuel isconfigured to supplement a primary fuel used by the compression-ignitionengine. The first pressure regulator is configured to be positioneddownstream of the supplemental fuel tank. The first pressure regulatoris configured to reduce a pressure of the supplemental fuel receivedfrom the supplemental fuel tank from a first pressure to a secondpressure. The second pressure regulator is configured to be positioneddownstream of the first pressure regulator. The second pressureregulator is configured to reduce the pressure of the supplemental fuelreceived from the first pressure regulator from the second pressure to athird pressure. The fuel mixer is configured to be positioned downstreamof the second pressure regulator. The fuel mixer includes a nozzle, astem, and a valve assembly. The nozzle is configured to be positionedwithin a conduit of an air supply system for the compression-ignitionengine. The nozzle is configured to receive a flow of the supplementalfuel and provide the supplemental fuel to air flowing through theconduit. The stem is configured to extend through a wall of the conduitand interface with the nozzle. The valve assembly includes (i) a valvebody defining (a) a valve body inlet configured to receive the flow ofthe supplemental fuel from the second pressure regulator and (b) a valvebody outlet interfacing with the stem and (ii) an adjuster positioned tofacilitate selectively restricting an amount of the flow of thesupplemental fuel through the valve body outlet and provided to the stemand the nozzle. The electronic lock off valve is configured to bepositioned between the supplemental fuel tank and the fuel mixer. Thetemperature sensor is configured to acquire temperature data regarding atemperature of the compression-ignition engine. The controller isconfigured to monitor the temperature of the compression-ignition enginebased on the temperature data acquired by the temperature sensor,compare the temperature to a temperature range, and control theelectronic lock off valve such that the electronic lock off valve isclosed to prevent the supplemental fuel from being provided to the airsupply system in response to the temperature being outside of thetemperature range.

This summary is illustrative only and is not intended to be in any waylimiting. Other aspects, inventive features, and advantages of thedevices or processes described herein will become apparent in thedetailed description set forth herein, taken in conjunction with theaccompanying figures, wherein like reference numerals refer to likeelements.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is schematic block diagram of a machine having a first fuelsystem, an air supply system, and a second fuel system, according to anexemplary embodiment.

FIG. 2 is a schematic view of a portion of the air supply system and thesecond fuel system of FIG. 1 , according to an exemplary embodiment.

FIG. 3 is a cross section view of the portion of the air supply systemand the second fuel system of FIG. 2 , according to an exemplaryembodiment.

FIG. 4 is a side view of a portion of the second fuel system of FIG. 1 ,according to an exemplary embodiment.

FIG. 5 is a front perspective view of the portion of the second fuelsystem of FIG. 4 , according to an exemplary embodiment.

FIG. 6 is another front perspective view of the portion of the secondfuel system of FIG. 4 , according to an exemplary embodiment.

FIG. 7 is a rear perspective view of the portion of the second fuelsystem of FIG. 4 , according to an exemplary embodiment.

FIG. 8 is a cross sectional view of the portion of the second fuelsystem of FIG. 4 , according to an exemplary embodiment.

FIG. 9 is a block diagram of a control system of the second fuel systemof FIG. 1 , according to an exemplary embodiment.

FIG. 10 shows a user interface of the control system of FIG. 9 ,according to an exemplary embodiment.

FIG. 11 is a flow diagram of a method for controlling the second fuelsystem of FIG. 1 based on voltage monitoring, according to an exemplaryembodiment.

FIG. 12 is a flow diagram of a method for controlling the second fuelsystem of FIG. 1 based on exhaust temperature monitoring, according toan exemplary embodiment.

FIG. 13 is a flow diagram of a method for controlling the second fuelsystem of FIG. 1 based on engine temperature monitoring, according to anexemplary embodiment.

DETAILED DESCRIPTION

Before turning to the figures, which illustrate certain exemplaryembodiments in detail, it should be understood that the presentdisclosure is not limited to the details or methodology set forth in thedescription or illustrated in the figures. It should also be understoodthat the terminology used herein is for the purpose of description onlyand should not be regarded as limiting.

According to an exemplary embodiment, a supplemental fuel system of thepresent disclosure facilitates supplementing a primary fuel system(e.g., a liquid fuel system, a diesel fuel system, etc.) with asupplemental fuel such as natural gas, propane, methane, or other fuel.The supplemental fuel system may include at least one fuel mixerconfigured to be at least partially disposed within an air supply system(e.g., in a conduit of the air supply system) of a vehicle. The fuelmixer may include a Venturi nozzle configured to generate a vacuumsignal to draw a low pressure supply of gaseous supplemental fuel intothe air supply system, which is ultimately mixed with the primary fuel(e.g., diesel) in the combustion chamber of the engine of the vehicle.In this manner, a supplemental gaseous fuel may be provided to theengine, which may reduce the rate of consumption of the primary fuel ofthe primary fuel system, reduce fueling costs, and improve engineperformance. According to an exemplary embodiment, the supplemental fuelsystem is configured as a universal conversion kit that can beretrofitted onto any compression-ignition driven system or vehicle.Therefore, the supplemental fuel system of the present disclosureeliminates the need to buy specific conversion kits for each differentvehicle or system.

Overall System

As shown in FIG. 1 , a machine, shown as vehicle 10, includes a vehicledriveline, shown as driveline 100. Generally, the driveline 100 includesa first fueling system, shown as primary fuel system 102, a prime mover,shown as engine 104, an inflow system, shown as air supply system 106,an outflow system, shown as exhaust system 108, an electrical energygenerator, shown as alternator 110, a power supply system, shown aspower supply 112, a second fueling system, shown as supplemental fuelsystem 200, and a control system, shown as supplemental fuel controlsystem 350. According to an exemplary embodiment, the engine 104 isconfigured to consume a first or primary fuel provided by the primaryfuel system 102 and a second, different or supplemental fuel provided bythe supplemental fuel system 200 to power the vehicle 10. In someembodiments, the supplemental fuel system 200 and the supplemental fuelcontrol system 350 are provided as a retrofit or conversion kit to beinstalled onto the vehicle 10 post-production. In some embodiments, thesupplemental fuel system 200 and the supplemental fuel control system350 are installed by an original equipment manufacturer (“OEM”) duringthe production of the vehicle 10.

In some embodiments, the vehicle 10 is an on-road vehicle. By way ofexample, the vehicle 10 may be a semi-tractor, a truck, a passengervehicle, a refuse vehicle, a concrete mixer vehicle, a response vehicle,a tow truck, a bucket truck, and/or another type of on-road vehicle. Insome embodiments, the vehicle 10 is an off-road vehicle. By way ofexample, the vehicle 10 may be mining machinery, agricultural machinery,construction machinery, marine vehicles, and/or another type of off-roadvehicle. In some embodiments, the vehicle 10 includes a chassissupported by one or more tractive elements (e.g., wheels, tracks, etc.).The tractive elements may be configured to facilitate motion of thevehicle 10. In some embodiments, the machine is a partially or fullystationary system, rather than a vehicle. For example, the machine maybe configured as a stationary or portable electrical generator.

According to an exemplary embodiment, the engine 104 is or includes acompression-ignition internal combustion engine. For example, the engine104 may be or may include a diesel engine. The engine 104 may beconfigured to convert energy stored in at least one fuel into amechanical force (e.g., a rotational force). For example, the engine 104may include one or more cylinders and one or more pistons movable withinthe one or more cylinders to rotate an output shaft (e.g., acrankshaft). In some embodiments, one or more mechanical output devices(e.g., the alternator 110, a transmission, driveshaft, one or moreaxles, one or more tractive elements, a hybrid drive system, a hybridbattery charger/generator, an accessory, etc.) are mechanically drivenby the engine 104.

According to an exemplary embodiment, the primary fuel system 102 isconfigured to store and provide a first or primary fuel to the engine104. The primary fuel system 102 may include a plurality of componentsto store and provide the first or primary fuel to the engine 104. By wayof example, the primary fuel system 102 may include a fuel storagedevice (e.g., a fuel tank, a fuel container, etc.), a water separator(e.g., a fuel water separator), a fuel filter, a fuel pump, and/or stillother fueling system components. The plurality of components of theprimary fuel system 102 may be fluidly coupled. The fuel storage devicemay store, contain, or hold the first or primary fuel (e.g., a liquidfuel such as diesel, biodiesel, SVO, kerosene, mixtures thereof, and/orany other suitable liquid fuel for use in a compression-ignitioncombustion engine). The fuel storage device may include an inlet and anoutlet. The inlet of the fuel storage device may facilitate a usermanipulating the fuel and/or a quantity of fuel in the fuel storagedevice. For example, a user may add fuel or add an additive to the fuelstorage device through the inlet.

In some embodiments, the fuel storage device is fluidly connected to thewater separator, the fuel filter, and/or the fuel pump. The waterseparator may be configured to at least partially remove water from thefirst or primary fuel. The fuel filter may be configured to at leastpartially remove particulates or debris within the first or primaryfuel. The fuel pump may be configured to pump the first or primary fuelfrom the fuel storage device and through the primary fuel system 102 tothe engine 104 (e.g., a fuel injector system thereof). The fuel pump maybe in communication with a controller (e.g., an engine controller, amicroprocessor, a processing circuit, etc.).

As shown in FIG. 1 , the air supply system 106 includes one or more airinlets, shown as air intake 120, a cleaning device (e.g., a purifyingdevice, a fluid cleaning device, etc.), shown as air cleaner 122, aforced induction device, shown as turbocharger 124, and a heat exchanger(e.g., air-to-air cooler, an aftercooler, a charged cooler, a turbocooler, an intercooler, a charge air cooler, a radiator, etc.), shown asair cooler 130. The components of the air supply system 106 (e.g., theair intake 120, the air cleaner 122, the turbocharger 124, the aircooler 130, etc.) may be fluidly connected by one or more conduits(e.g., pipes, tubes, etc.). As shown in FIG. 1 , the air intake 120, theair cleaner 122, the turbocharger 124, and the air cooler 130 arearranged in series such that air received by the air intake 120 flowssequentially through the air intake 120, the air cleaner 122, theturbocharger 124, and the air cooler 130 before ultimately beingprovided to and received by the engine 104. In some embodiments, one ormore of the components of the air supply system 106 are arrangeddifferently (e.g., in parallel, in a different order, etc.).

According to an exemplary embodiment, the air cleaner 122 is configuredto remove debris and/or particulate matter from the air entering the airsupply system 106. For example, the air cleaner 122 may be or mayinclude at least one of a dry air cleaner (e.g., a paper filter aircleaner, a mesh air cleaner, a wire air cleaner, etc.), a fluid enhanced(e.g., oil) air cleaner (e.g., an oil wetted air cleaner, an oil bathair cleaner, etc.), a mechanical air filter (e.g., a centrifugal aircleaner), or another suitable air cleaner. In some embodiments, the aircleaner 122 includes or defines the air intake 120. In otherembodiments, the air intake 120 is or includes an inlet (e.g., opening)and/or a conduit including an air inlet (e.g., a vehicle snorkel, a hoodscoop, an intake cowl, etc.).

As shown in FIG. 1 , the turbocharger 124 includes a first or air sidedevice, shown as compressor 126, and a second or exhaust side device,shown as turbine 128. The compressor 126 is positioned along the airsupply system 106 between the air cleaner 122 and the air cooler 130,upstream of the engine 104. The turbine 128 is positioned along theexhaust system 108, downstream of the engine 104. The compressor 126 mayinclude (i) a first or compressor housing that defines a first orcompressor inlet and a first or compressor outlet and (ii) a first orcompressor wheel disposed within the compressor housing. The turbine 128may include (i) a second or turbine housing that defines a second orturbine inlet and a second or turbine outlet and (ii) a second orturbine wheel disposed within the turbine housing. The compressor wheelof the compressor 126 may be coupled to the turbine wheel of the turbine128. For example, the turbine wheel and the compressor wheel may berotatably coupled by a rigid member or shaft. The shaft may be supportedby one or more bearings of the turbocharger 124. According to anexemplary embodiment, the turbine 128 is configured to be driven byexhaust gases received from the exhaust system 108, which causes thecompressor 126 draw in air through the air supply system 106 into thecompressor inlet of the compressor housing and output compressed air ata higher pressure and temperature through the compressor outlet of thecompressor housing.

In some embodiments, the air supply system 106 additionally oralternatively includes a supercharger (e.g., an engine-poweredcompressor). In some embodiments, the air supply system 106 includes twoor more forced induction devices (e.g., turbochargers, superchargers,etc.), which may be located in parallel or in series with each other.For example, the turbocharger 124 may be or may include a twinturbocharger configuration. In some embodiments, the engine 104 isnaturally aspirated.

As shown in FIG. 1 , an inlet of the air cooler 130 is fluidly coupledto the compressor outlet of the compressor 126 of the turbocharger 124.According to an exemplary embodiment, the air cooler 130 includes one ormore heat exchangers configured to cool the compressed air received fromthe compressor 126 of the turbocharger 124 as the compressed air flowsthrough the air cooler 130. In one embodiment, the air cooler 130includes a conduit extending between the inlet and an outlet thereofthat is configured to direct the compressed air received from thecompressor 126 through one or more heat transfer devices (e.g., fins,tubes, pipes, etc.), which are configured (e.g., shaped, sized, etc.) toextract heat therefrom. In some embodiments, the air cooler 130 includesa second conduit and/or passage between a second inlet and a secondoutlet thereof that is configured to receive and direct a second fluid(e.g., a cooling working fluid) that absorbs and/or transports the heatextracted from the compressed air away from the air cooler 130 (e.g., tothe ambient environment, to a heat sink, to a supplemental heatexchanger, to a reservoir, etc.). By way of example, the air cooler 130may be configured to cool the compressed air flowing therethrough suchthat the density of the compressed air increases before exiting the aircooler 130. The compressed, cooled air may thereafter be provided fromthe air cooler 130 to the engine 104. It is important to note that theair supply system 106 and the components thereof, in cooperation withthe supplemental fuel system 200, may supply any gas or mixture of gases(e.g., atmospheric air, gaseous fuel, gaseous additives, etc.) to theengine 104, as described in more detail herein.

As shown in FIG. 1 , the engine 104 includes a primary fuel injectionsystem, shown as fuel injection system 140, coupled to the primary fuelsystem 102; a first manifold, shown as intake manifold 142, coupled tothe air cooler 130; and a second manifold, shown as exhaust manifold144, coupled to the exhaust system 108. The fuel injection system 140may include at least one fuel injector per cylinder of the engine 104.The fuel injector may include an injection pump, an injector nozzle,and/or a fuel system sensor (e.g., a pressure sensor, a temperaturesensor, a flow sensor, a fuel sensor, etc.). The injection pump may beconfigured to generate an injection pressure (e.g., a pressuresufficient to at least partially atomize the primary fuel when theprimary fuel is forced through the injector nozzle and sprayed into thecombustion chamber of the cylinder). The injection pump may be the sameas or different than the fuel pump of the primary fuel system 102. Theinjector nozzle may be positioned downstream of the injector pump andmay be at least partially disposed within the combustion chamber and/ormay be proximate the combustion chamber. For example, the injectornozzle may be positioned and configured to selectively supply a meteredamount of the primary fuel directly to a combustion chamber (i.e., adirect fuel injection) and/or indirectly to the combustion chamber via acomponent upstream the combustion chamber (i.e., an indirect fuelinjection).

The intake manifold 142 may be configured (e.g., via tubes, pipes,channels, cavities, flow paths, etc.) to evenly distribute air and/orsupplemental fuel (e.g., the compressed/cooled air, a combination of thecompressed/cooled air and supplemental fuel, etc.) received from the aircooler 130 of the air supply system 106 to the one or more cylinders ofthe engine 104. The one or more cylinders of the engine 104 may,therefore, receive (i) the primary fuel from the primary fuel system 102through the fuel injection system 140, (ii) the compressed/cooled airfrom the air supply system 106 through the intake manifold 142, and(iii) the supplemental fuel from the supplemental fuel system 200through the air supply system 106 and the intake manifold 142. Theengine 104 may, therefore, perform a combustion-ignition process withineach of the one or more cylinders thereof using the primary fuel, thecompressed/cooled air, and/or the supplemental fuel to power the vehicle10 and/or components thereof. The exhaust manifold 144 may be configuredto collect exhaust gases produced as a byproduct of thecombustion-ignition process from the one or more cylinders of the engine104 and provide the exhaust gases to the exhaust system 108.

As shown in FIG. 1 , the exhaust system 108 includes an exhaustassembly, shown as exhaust 150, and an exhaust opening, shown as exhaustoutlet 152. The exhaust 150 may be configured to reduce emissions ofpollutants (e.g., products of combustion such as carbon dioxide, carbonmonoxide, sulfur dioxide, nitrogen oxides, lead, particulate matter,etc.), attenuate noise, and/or direct the exhaust gases from the engine104 through the turbine 128 of the turbocharger 124 and to the exhaustoutlet 152. For example, the exhaust 150 may include a catalyticconverter, a selective catalytic reduction (“SCR”) system, an exhaustgas recirculation (“EGR”) system, a particulate filter (e.g., a dieselparticulate filter (“DPF”), etc.), a muffler (e.g., silencer, damper,suppressor, baffle system, etc.), and/or one or more conduits (e.g.,piping, downpipe, headers, mid-pipe, exhaust pipe, tailpipe, etc.).According to an exemplary embodiment, the exhaust gases flowing throughthe exhaust system 108 pass through the turbine 128 of the turbocharger124 such that the exhaust gases drive the turbine 128 to rotate.Rotation of the turbine 128, thereby, drives rotational motion of thecompressor 126. The rotation of the compressor 126 may compress the airentering the air supply system 106, which may increase the performanceof the engine 104 and improve fuel efficiency. The components of theexhaust 150 may be fluidly connected in series and/or in parallelbetween the engine 104 and the exhaust outlet 152.

As shown in FIG. 1 , the engine 104 is configured to drive thealternator 110. The alternator 110 may be configured to convert at leasta portion of the mechanical output from the engine 104 into electricalenergy. As shown in FIG. 1 , the alternator 110 is electrically coupledto the power supply 112 and may be configured to supply the electricalenergy generated thereby to the power supply 112 to charge the powersupply 112. The power supply 112 may be electrically coupled (e.g.,wired) to the alternator 110. The power supply 112 may be or may includean electrical energy storage device (e.g., a capacitor, a battery, alead-acid battery, a battery cell, a battery cell array, etc.) and/or anelectrical regulator (e.g., a voltage regulator, a fuse, a diode, arectifier, an inverter, etc.). In some embodiments, the driveline 100includes two or more alternators 110 and/or two or more power supplies112.

In some embodiments, the power supply 112 is configured to supplyelectricity (e.g., electric power) to some or all of the electricalcomponents of the vehicle 10. For example, the power supply 112 mayprovide electrical energy to the engine 104 (e.g., an electric starter,an engine control unit (“ECU”), position sensors, rotation sensors,temperature sensors, pressure sensors, an electrically drivenlubricating oil pump, an electronic fuel injector system, etc.), theprimary fuel system 102 (e.g., an electronic fuel pump, etc.), theexhaust system 108 (e.g., electronic exhaust valves, exhaust sensors,etc.), the supplemental fuel system 200 (e.g., electronic valves, etc.),the supplemental fuel control system 350 (e.g., sensors, a controller, auser interface, etc.), and/or other electronic vehicle accessoriesand/or subsystems (e.g., electronic power steering, a vehicle lightingsystem, a vehicle sensor system, a vehicle infotainment system, avehicle user interface, a sound system, an HVAC system, etc.).

In some embodiments, the engine 104 includes an ECU (e.g., an enginecontroller, a microprocessor, a processing circuit, etc.) configured tocontrol at least one engine operation or parameter of the engine 104.According to an exemplary embodiment, the ECU is separate from thesupplemental fuel control system 350 (e.g., when the supplemental fuelcontrol system 350 is provided in a retrofit or conversion kit). In someembodiments, the vehicle 10 includes a supervisory controller thatcontrols the ECU and the supplemental fuel control system 350. In someembodiments, the ECU and the supplemental fuel control system 350 areone in the same (e.g., when the supplemental fuel system 200 and thesupplemental fuel control system 350 are installed by an OEM during theproduction of the vehicle 10).

Supplemental Fuel System

As shown in FIGS. 1 and 2 , the supplemental fuel system 200 includes afuel storage device, shown as pressurized fuel tank 202, a firstpressure regulator, shown as high pressure regulator 204, a firstcontrol valve, shown as first electronic lock off 206, a second controlvalve, shown as second electronic lock off 208, a second pressureregulator, shown as low pressure regulator 210, and a mixing device(e.g., an injector, a mixer, a nozzle device, a Venturi device, etc.),shown as fuel mixer 220. In some embodiments, the supplemental fuelsystem 200 does not include one of the high pressure regulator 204 orthe low pressure regulator 210. In some embodiments, the supplementalfuel system 200 does not include one of the first electronic lock off206 or the second electronic lock off 208.

The pressurized fuel tank 202 may be configured to store, contain, orhold the second or supplemental fuel that is different than the primaryfuel of the primary fuel system 102. For example, the pressurized fueltank 202 may be a canister for storing a compressed, gaseous fuel or aliquefied fuel. In some embodiments, the supplemental fuel is acompressed, gaseous fuel. In one embodiment, the compressed, gaseousfuel is compressed natural gas (“CNG”). In other embodiments, thecompressed, gaseous fuel is another type of compressed, gaseous fuel(e.g., methane, hydrogen, etc.) or any mixture or combination thereof.In some embodiments, the supplemental fuel is a liquefied fuel (e.g.,liquefied natural gas, liquid propane, etc.).

As shown in FIGS. 1 and 2 , the outlet of the pressurized fuel tank 202is fluidly coupled to the high pressure regulator 204. The high pressureregulator 204 may be configured as a pressure reducing regulator. Forexample, the high pressure regulator 204 may be configured to reduce thepressure of the supplemental fuel received from the pressurized fueltank 202 to a first controlled pressure or a first target pressure atthe outlet of the high pressure regulator 204. In other words, the highpressure regulator 204 may be configured to output the supplemental fuelat a desired pressure when supplied with the supplemental fuel at apressure above the first target pressure. In some embodiments, thepressurized fuel tank 202 stores and supplies the supplemental fuel at astorage or high pressure (e.g., between 200 and 4,000 psi; 3,600 psi;etc.). In such embodiments, the high pressure regulator 204 may beconfigured to reduce the pressure of the supplement fuel from the highpressure to the first target pressure. In some embodiments, the firsttarget pressure is a predetermined value (e.g., about 200 psi, about 150psi, etc.). The first target pressure may be or include a thresholdvalue (e.g., less than 200 psi, less than 150 psi, etc.), or a range ofthreshold values (e.g., between 100 psi and 200 psi). For example, thehigh pressure regulator 204 may be configured to reduce the pressure ofthe gaseous fuel to between 100 psi to 200 psi based on an inputpressure between 200 psi and 4,000 psi. In some embodiments, the highpressure regulator 204 is configured to facilitate vaporization of thesupplemental fuel as the pressure thereof is decreased (e.g., ifreceived from pressurized fuel tank 202 in a liquid form, etc.).

As shown in FIGS. 1 and 2 , the high pressure regulator 204 ispositioned upstream of the first electronic lock off 206 and the firstelectronic lock off 206 is positioned upstream of the second electroniclock off 208 and the low pressure regulator 210. In other embodiments,the first electronic lock off 206 is positioned upstream of the highpressure regulator 204. In some embodiments, the supplemental fuelsystem 200 does not include the first electronic lock off 206. As shownin FIGS. 1 and 2 , the second electronic lock off 208 is positioneddownstream of the first electronic lock off 206 and upstream of the lowpressure regulator 210. In other embodiments, the second electronic lockoff 208 is positioned downstream of the low pressure regulator 210. Insome embodiments, the supplemental fuel system 200 does not include thesecond electronic lock off 208.

The first electronic lock off 206 and/or the second electronic lock off208 may include an actuator and a valve configured to facilitateselectively controlling or inhibiting the flow of the supplemental fuelthrough the first electronic lock off 206. In one embodiment, the firstelectronic lock off 206 and/or the second electronic lock off 208 are orinclude a normally-closed valve configured to be biased closed and opensuch that the supplemental fuel flows through the first electronic lockoff 206 and/or the second electronic lock off 208 in response a currentor electronic signal being supplied thereto (e.g., by the supplementalfuel control system 350). In another embodiment, the first electroniclock off 206 and/or the second electronic lock off 208 are or include anormally-open valve configured to be biased open and close such that thesupplemental fuel does not flow through the first electronic lock off206 and/or the second electronic lock off 208 in response a current orelectronic signal being supplied thereto (e.g., by the supplemental fuelcontrol system 350). In still another embodiment, the first electroniclock off 206 and/or the second electronic lock off 208 are or include anunbiased valve. As used herein, an unbiased valve refers to any valvethat is not biased by a spring or otherwise toward a closed position oran open position. Unbiased valves can include one or more actuators(e.g., electric solenoids) that act on a valve element to move the valveelement between the open position and the closed position. In someembodiments, the first electronic lock off 206 and/or the secondelectronic lock off 208 include a check valve such that the supplementalfuel flows in a single direction therethrough.

As shown in FIGS. 1 and 2 , the low pressure regulator 210 is positionedto receive the supplemental fuel in a gaseous state at the first targetpressure (e.g., from the high pressure regulator 204, from the firstelectronic lock off 206, from the second electronic lock off 208, etc.).The low pressure regulator 210 may be configured as a pressure reducingregulator. For example, the low pressure regulator 210 may be configuredto reduce the pressure of the supplemental fuel that enters the inlet ofthe low pressure regulator 210 to a second controlled pressure or asecond target pressure at the outlet of the low pressure regulator 210.In other words, the low pressure regulator 210 may be configured tooutput the supplemental fuel at a desired pressure when supplied thesupplemental fuel at a pressure above the second target pressure.According to an exemplary embodiment, the high pressure regulator 204 isconfigured to supply the supplemental fuel to the inlet of the lowpressure regulator 210 at the first target pressure. The low pressureregulator 210 may be configured to further reduce the pressure of thesupplemental fuel from the first target pressure to the second targetpressure. In one embodiment, the second target pressure is a low or nearzero pressure (e.g., about 3 inches water, about 0.1 psi, less than 3inches water, less than 0.2 psi, etc.). In this way, the supplementalfuel may be stored at high pressure (e.g., 3600 psi) and pass throughone or more pressure regulators (e.g., the high pressure regulator 204and/or the low pressure regulator 210) to achieve the low or near zeropressure. In some embodiments, the low pressure regulator 210 isnormally closed unless a vacuum signal is present at the outlet of thelow pressure regulator 210. In such embodiments, the low pressureregulator 210 is configured to supply the supplemental fuel in responseto the vacuum. The amount of fuel supplied by the low pressure regulator210 may be based on the amount of vacuum present at the outlet thereof(e.g., the greater the vacuum, the more open the low pressure regulator210 may become, etc.). In some embodiments, the low pressure regulator210 includes a vacuum switch. In some embodiments, the low pressureregulator 210 is a PEV-01-08 regulator. In some embodiments, the lowpressure regulator 210 is a two-stage regulator.

As shown in FIGS. 1 and 2 , the outlet of the low pressure regulator 210is coupled to an inlet the fuel mixer 220. Generally, the fuel mixer 220may positioned such that (i) a first inlet of the fuel mixer 220 isdownstream of the air intake 120 (e.g., within the air cleaner 122,downstream of the air cleaner 122, upstream of the compressor 126 of theturbocharger 124, etc.), (ii) a second inlet of the fuel mixer 220 isdownstream of the pressurized fuel tank 202 and/or at least oneregulator (e.g., the high pressure regulator 204, the low pressureregulator 210, etc.), and (iii) an outlet of the fuel mixer 220 ispositioned upstream of the engine 104 (e.g., upstream of the compressor126 of the turbocharger 124). According to an exemplary embodiment, thefuel mixer 220 is configured to mix two or more fluids. In the currentimplementation, the fuel mixer 220 is configured to (i) mix (a) the airflowing into and through the air supply system 106 and (b) thesupplemental gaseous fuel provided by the low pressure regulator 210 and(ii) output the mixture to the downstream components of the air supplysystem 106 (e.g., the turbocharger 124, the air cooler 130, etc.) and/orthe engine 104. According to the exemplary embodiment shown in FIG. 1 ,the fuel mixer 220 is positioned to output the mixture to the inlet ofthe compressor 126 of the turbocharger 124. In some embodiments, thefuel mixer 220 is coupled to or formed in other components of the airsupply system 106. For example, the fuel mixer 220 can be installedinside the air cleaner 122 or a conduit that is fluidly coupled to oneor more of the components of the air supply system 106.

Fuel Mixer Construction

As shown in FIGS. 2-8 , the fuel mixer 220 includes a first portion or afuel mixer portion, shown as nozzle 222; a second portion or fuel supplyportion, shown as stem assembly 240, coupled to the nozzle 222; and athird portion or a control valve portion, shown as fuel flow valve 260,coupled to the stem assembly 240. In some embodiments, the components ofthe fuel mixer 220 are manufactured from at least one rigid material.For example, the nozzle 222, the stem assembly 240, the fuel flow valve260, and/or the components thereof may be manufactured from a variety ofmaterials including metals (e.g., steel, stainless steel, aluminum,titanium, etc.), metal alloys (e.g., brass, aluminum alloys, etc.),plastics (e.g., thermoset, thermoplastic, resin, etc.), compositematerials (e.g., carbon fiber reinforced plastic, etc.), organicmaterials, inorganic materials, and/or other suitable materials.

As shown in FIGS. 2 and 8 , the nozzle 222 defines a first axis, shownas longitudinal axis 226. As shown in FIGS. 2-8 , the nozzle 222includes a peripheral sidewall or housing, shown as nozzle body 228,having a first surface, shown as inner surface 227, a second surface,shown as outer surface, a first end, shown as inlet end 230, and anopposing second end, shown as outlet end 232. As shown in FIGS. 2,3, and5-8 , the nozzle 222 defines a passage, shown as nozzle passage 233,extending along the longitudinal axis 226 from the inlet end 230 to theoutlet end 232 of the nozzle body 228. As shown in FIGS. 3 and 5-8 , thenozzle body 228 defines a first inlet, shown as supplemental fuel inlet235, that leads to the nozzle passage 233. In some embodiments, thesupplemental fuel inlet 235 includes a plurality of inlets positionedradially around nozzle body 228 (e.g., in one or more rings defined bythe inner surface 227, longitudinally spaced along the nozzle body 228,etc.). In such embodiments, the nozzle body 228 may define an internalpassage that fluidly connects the plurality of inlets.

According to the exemplary embodiment shown in FIGS. 2 and 8 , the outersurface 229 of the nozzle body 228 has a substantially uniform andsymmetric profile (e.g., a cylindrical profile, etc.) and the innersurface 227 of the nozzle body 228 has a non-uniform or asymmetricprofile (i.e., asymmetry between a first or inlet taper positioned atthe inlet end 230 and a second or outlet taper positioned at the outletend 232). As shown in FIG. 8 , the nozzle body 228 has a firsttransition point, shown as inlet transition point 234, and a secondtransition point, shown as outlet transition point 236. The innersurface 227 defines (i) a first taper, shown as inlet taper 237, thatextends from the inlet end 230 to the inlet transition point 234 at afirst angle and (ii) a second taper, shown as outlet taper 239, thatextends from the outlet end 232 to the outlet transition point 236 at asecond angle different than the first angle of the inlet taper 237.According to an exemplary embodiment, the first angle is greater thanthe second angle (i.e., the inlet taper 237 is substantially more abruptthan the outlet taper 239 and the outlet taper 239 is substantially moregradual than the inlet taper 237). According to an exemplary embodiment,a ratio of an outlet longitudinal length of the outlet taper 239 to aninlet longitudinal length of the inlet taper 237 is greater than one(e.g., 2, 3, 4, etc.).

As shown in FIGS. 2 and 5-8 , the inlet end 230, the outlet end 232, andthe inner surface 227 define and shape the nozzle passage 233 such thatthe nozzle passage 233 has a non-uniform profile, show as flow profile280. The flow profile 280 includes (i) a first portion that defines asecond inlet of the nozzle 222, shown as air inlet 282, defined by theinlet end 230 and the inlet taper 237, (ii) a second portion (e.g.,narrow portion, a constriction portion, choke portion, throat portion,an intermediate portion, etc.), shown as mixing chamber 284, extendingbetween the inlet transition point 234 and the outlet transition point236, and (iii) a third portion the defines an outlet of the nozzle 222,shown as mixture outlet 286, defined by the outlet end 232 and theoutlet taper 239.

According to an exemplary embodiment, the inner surface 227 of thenozzle body 228 is shaped such that the cross-sectional dimension of theflow profile 280 varies along the longitudinal axis 226 with (i) thecross-sectional dimension decreasing along the first portion of the flowprofile 280 with inlet taper 237 from the inlet end 230 to the inlettransition point 234 and (ii) the cross-sectional dimension increasingalong the third portion of the flow profile 280 with the outlet taper239 from the outlet transition point 236 to the outlet end 232.According to an exemplary embodiment, the flow profile 280 is configuredto provide a Venturi effect or functionality that facilitates generatinga vacuum signal, as described in greater detail herein.

As shown in FIG. 8 , the nozzle 222 has a first dimension, shown asnozzle length 312, a second dimension, shown as mixing chamber diameter314, a third dimension, shown as nozzle outer diameter 318, a fourthdimension, shown as nozzle wall thickness 320, a fifth dimension, shownas nozzle inlet length 322, a sixth dimension, shown as mixing chamberlength 324, a seventh dimension, shown as nozzle outlet length 326, andan eighth dimension, shown as fuel inlet position 328. The nozzle length312 is the entire longitudinal length of the nozzle body 228 between theinlet end 230 and the outlet end 232, and is parallel to thelongitudinal axis 226. The mixing chamber diameter 314 is the smallestradial distance between opposing portions of the inner surface 227 alongthe mixing chamber 284 and the longitudinal axis 226. In someembodiments, the mixing chamber diameter 314 is substantially uniform.In other embodiments, the mixing chamber diameter 314 slightly tapersbetween the inlet transition point 234 and the outlet transition point236. The nozzle outer diameter 318 is the diameter of the outer surface229 of the nozzle 222 and is larger than the mixing chamber diameter314. In some embodiments, the nozzle outer diameter 318 is substantiallyuniform. In other embodiments, the nozzle outer diameter 318 isnon-uniform (e.g., slightly tapers between the inlet end 230 and theoutlet end 232, the outer surface 229 does not have a cylindricalprofile, etc.). The nozzle wall thickness 320 is defined between theouter surface 229 and inner surface 227 of the nozzle body 228 of thenozzle 222, which varies along the longitudinal axis 226 between theinlet end 230 and the outlet end 232 of the nozzle 222. The nozzle inletlength 322 is the distance along the longitudinal axis 226 between theinlet end 230 and the inlet transition point 234 where the mixingchamber 284 begins (i.e., the longitudinal length of the inlet taper237). The mixing chamber length 324 is the length of the mixing chamber284 along the longitudinal axis 226 defined between the inlet transitionpoint 234 and the outlet transition point 236. The nozzle outlet length326 is the distance along the longitudinal axis 226 between the outlettransition point 236 where the mixing chamber 284 ends and the outletend 232 (i.e., the longitudinal length of the outlet taper 239). Thefuel inlet position 328 defines the position of the supplemental fuelinlet 235 along the mixing chamber 284. Specifically, the fuel inletposition 328 is defined as the distance between the inlet transitionpoint 234 and a center point of the supplemental fuel inlet 235.

According to an exemplary embodiment, the nozzle length 312 is about 4inches, the mixing chamber diameter 314 is about 2 inches, the nozzleouter diameter 318 is about 3 inches, the nozzle wall thickness 320 isat most about 0.5 inches, the nozzle inlet length 322 is about 0.5inches, the mixing chamber length 324 is about 2 inches, and the nozzleoutlet length 326 is about 1.5 inches. Stated differently, the mixingchamber diameter 314 is about 50% or one-half of the nozzle length 312and 66.7% or two-thirds of the nozzle outer diameter 318, the nozzleouter diameter 318 is about 75% or three-fourths of the nozzle length312, the nozzle wall thickness 320 is about 25% or one-fourth of themixing chamber diameter 314 and about 16.7% or one-sixth of the nozzleouter diameter 318, the nozzle inlet length 322 is about 12.5% orone-eighth of the nozzle length 312, the mixing chamber length 324 isabout 50% or one-half of the nozzle length 312 and about the same as themixing chamber diameter 314, and the nozzle outlet length 326 is about37.5% or three-eighths of the nozzle length 312. Accordingly, the nozzleoutlet length 326 is about three times longer than the nozzle inletlength 322, the nozzle inlet length 322 is about one-fourth of themixing chamber length 324, and the nozzle outlet length 326 is aboutthree-quarters of the of the mixing chamber length 324. Applicant hasidentified, through various research, development, testing, and designiterations, that the dimensions and proportions of the nozzle 222outlined above provide an enhanced Venturi functionality for thepurposes of the application of the fuel mixer 220 disclosed herein.

In some embodiments, the proportions of the nozzle 222 are maintained,but the dimensions are varied (e.g., for a larger or smaller system). Insuch embodiments, the proportions of the nozzle 222 may be maintained,but the dimensions may be increased or decreased. By way of example, thenozzle 222 may have the same proportions as outlined above, but thedimensions may be half the scale. By way of another example, the nozzle222 may have the same proportions as outlined above, but the dimensionmay be double, three times, etc. the scale.

In some embodiments, the proportions of the nozzle 222 and thedimensions of the nozzle are varied (e.g., for different applications ofthe fuel mixer 220, to vary the Venturi functionality of the fuel mixer220, etc.). By way of example, the nozzle length 312 may range between 2inches and 12 inches (e.g., 2 inches, 3 inches, 4.5 inches, 6 inches, 8inches, 10 inches, etc.) or other suitable lengths. By way of anotherexample, the mixing chamber diameter is 314 may range between 1 inch and6 inches (e.g., 1.5 inches, 2.5 inches, 3 inches, 4 inches, 5 inches,etc.), or other suitable diameters. By way of another example, thenozzle wall thickness 320 may range between 0.25 inches and 1 inch. Byway of another example, the mixing chamber length 324 may range betweena negligible length (e.g., a single point) and 6 inches (e.g., 0.5inches, 1 inch, 2 inches, 3 inches, 6 inches, etc.), or other suitablelengths. By way of another example, the nozzle inlet length 322 mayrange between 0.25 inches and 2 inches (e.g., 0.25 inches, 0.75 inches,1 inch, 1.25 inches, 1.5 inches, etc.), or other suitable lengths. Byway of another example, the nozzle outlet length 326 may range be 0.5inches and 6 inches (e.g., 0.5 inches, 1 inch, 2 inches, 3 inches, 5inches, etc.), or other suitable lengths.

According to the exemplary embodiment shown in FIG. 8 , the fuel inletposition 328 of the supplemental fuel inlet 235 is selected such thatthe fuel inlet is positioned closer to the outlet transition point 236and the outlet taper 239 than the inlet transition point 234 and theinlet taper 237 (i.e., the fuel inlet position 328 is a majority of themixing chamber length 324). In other embodiments, the fuel inletposition 328 of the supplemental fuel inlet 235 is selected such thatthe supplemental fuel inlet 235 is positioned closer to the inlettransition point 234 and the inlet taper 237 than the outlet transitionpoint 236 and the outlet taper 239 (i.e., the fuel inlet position 328 isa minority of the mixing chamber length 324). In still otherembodiments, the fuel inlet position 328 of the supplemental fuel inlet235 is selected such that the supplemental fuel inlet 235 is positionedat the middle of the mixing chamber 284 (i.e., the fuel inlet position328 is one-half of the mixing chamber length 324).

As shown in FIGS. 2-8 , the stem assembly 240 includes a hollow memberor conduit, shown as stem 242. In one embodiment, the stem 242 has aunitary construction. In other embodiments, the stem 242 is manufacturedfrom multiple sections that may be coupled together. For example, afirst portion of the stem 242 may be welded, bonded, fastened, orotherwise attached to a second portion of the stem 242. As shown inFIGS. 2-8 , the stem 242 includes a sidewall, shown as sidewall 247,that defines passage, shown as stem passage 244, that extends along acentral axis, shown as axis 246, of the stem 242 between a first end,shown as nozzle end 248, and an opposing second end, shown as valve end250, thereof. One or more portions of the sidewall 247 of the stem 242may include male and/or female threading. As shown in FIGS. 3 and 8 ,(i) the nozzle end 248 of the stem 242 interfaces with and is receivedby the supplemental fuel inlet 235 of the nozzle 222 and (ii) the valveend 250 interfaces with and is received by a portion of the fuel flowvalve 260 (e.g., an outlet thereof). In some embodiments, (i) the nozzleend 248 of the stem 242 and the supplemental fuel inlet 235 and (ii) thevalve end 250 and the portion of the fuel flow valve 260 havecorresponding threads that mesh to secure (a) the nozzle end 248 withinthe supplemental fuel inlet 235 and (b) the valve end 250 within theportion of the fuel flow valve 260.

As shown in FIGS. 3-5, 7, and 8 , the stem assembly 240 includes (i) apair of seals (e.g., o-rings, rubber washers, sealant, etc.), shown asseals 298, disposed along the stem 242 and (ii) a pair of fasteners(e.g., clamps, nuts, etc.), shown as fasteners 300, disposed along thestem 242 between the nozzle end 248 and the valve end 250 of the stem242 and outside of the seals 298. According to an exemplary embodiment,the stem 242 and the fasteners 300 include corresponding threads thatmesh such that rotation of the fasteners 300 relative to the stem 242drives the fasteners 300 along the axis 246 of the stem 242 tofacilitate selectively adjusting the distance between the seals 298.

As shown in FIGS. 3-8 , the fuel flow valve 260 includes a body, shownas valve body 261, and an adjuster, shown as flow adjuster 270.According to an exemplary embodiment, the valve body 261 is configuredto fluidly couple the fuel mixer 220 to the rest of the supplementalfuel system 200 (e.g., via a conduit, etc.). As shown in FIGS. 3-8 , thevalve body 261 has a first end, shown as valve inlet end 262, and anopposing second end, shown as adjuster end 264. The valve body 261defines (i) an interior chamber, shown as valve chamber 267, (ii) afirst aperture, shown as inlet 266, providing access to the valvechamber 267, (iii) an interface including a second aperture, shown asoutlet 268, coupled to the valve chamber 267 and positioned between thevalve inlet end 262 and the adjuster end 264, and (iv) a passage, shownas adjuster passage 269, that extends from the valve chamber 267 throughthe adjuster end 264 of the valve body 261. According to an exemplaryembodiment, the inlet 266 of the valve body 261 is configured to couplewith the low pressure regulator 210 (e.g., via a conduit). As shown inFIGS. 3-8 , the outlet 268 of the valve body 261 interfaces with andreceives the valve end 250 of the stem 242 to couple the valve body 261to the nozzle 222.

According to an exemplary embodiment, the flow adjuster 270 isconfigured to facilitate selectively adjusting an amount of restrictionapplied to a fuel flow of the supplemental fuel through the valve body261 and provided to the nozzle 222 and the air supply system 106, andultimately the engine 104. By way of example, a portion of the flowadjuster 270 may be repositionable between a first position where theoutlet 268 of the valve body 261 is not restricted, a second positionwhere the outlet 268 of the valve body 261 is fully restricted, and aplurality of intermediate positions where the outlet 268 of the valvebody 261 is at least partially restricted. According to the exemplaryembodiment shown in FIGS. 4, 7, and 8 , the flow adjuster 270 ismanually and mechanically adjustable. In other embodiments, the flowadjuster 270 is electronically adjustable (e.g., via the supplementalfuel control system 350, in response to a user command, automatically,etc.).

As shown in FIGS. 4, 5, 7, and 8 , the flow adjuster 270 includes (i) arestrictor, shown as plunger 272, disposed and selectively translatablewithin the valve chamber 267 of the valve body 261, (ii) an actuator,shown as adjuster knob 274, positioned along an exterior of the valvebody 261, (iii) a shaft, shown as connector shaft 275, extending fromthe adjuster knob 274, through the adjuster passage 269 of valve body261, and to the plunger 272 disposed within the valve chamber 267, and(iv) a retaining member (e.g., a set screw, a lock nut, etc.), shown asretainer 276.

According to an exemplary embodiment, manipulating (e.g., turning,pressing in, pulling out, etc.) the adjuster knob 274 facilitatesadjusting the size of the valve chamber 267 and an amount of the outlet268 that is restricted by the plunger 272. By way of example, theadjuster knob 274 may be manipulated to selectively position the plunger272 to a fully open position, in which the plunger 272 does not restricta fuel flow of the supplemental fuel through the valve chamber 267 andthe outlet 268. By way of another example, the adjuster knob 274 may bemanipulated to selectively position the plunger 272 to a partiallyclosed position, in which the plunger 272 at least partially restricts afuel flow of the supplemental fuel through the valve chamber 267 and theoutlet 268. By way of yet another example, the adjuster knob 274 may bemanipulated to selectively position the plunger 272 to a closedposition, in which the plunger 272 fully restricts a fuel flow of thesupplemental fuel through the valve chamber 267 and the outlet 268.

In some embodiments, the fully open position and fully closed positionare defined by the maximum movable range of the plunger 272. Theposition of the plunger 272 may be is adjusted (e.g., by manipulatingthe adjuster knob 274) to accommodate various different fuel flowrequirements for various engines and/or desired performance parameters.For example, a first engine type may require less supplemental fuel dueto a high/overactive vacuum signal caused by a high flow rate of airthrough the air supply system 106. Therefore, the adjuster knob 274 maybe adjusted to move the plunger 272 toward the closed position, therebyfacilitating tuning the fuel mixer 220 for the specific engine. Once adesirable position for the plunger 272 has been set, the adjuster knob274 may be locked or fixed in place by the retainer 276 to preventinadvertent movement of the plunger 272 during use of the supplementalfuel system 200.

Fuel Mixer Positioning

As shown in FIGS. 1-3 , the fuel mixer 220 is integrated into the airsupply system 106. According to the exemplary embodiment shown in FIGS.1-3 , the fuel mixer 220 is integrated within a conduit 123 of the airsupply system 106, downstream of the air intake 120 and the air cleaner122, and upstream of the compressor 126 of the turbocharger 124, the aircooler 130, and the engine 104. In one embodiment, the fuel mixer 220 isinstalled inside of or integrated into the air cleaner 122 (e.g., thetubing of the air cleaner 122). By way of example, in such animplementation, a first end of the conduit 123 may terminate at the aircleaner 122 and an opposing second end of the conduit 123 may terminateat the compressor 126 of the turbocharger 124. In other embodiments, thefuel mixer 220 is otherwise positioned. By way of another example, thefuel mixer 220 may be integrated into the conduit 123 of the air supplysystem 106 downstream of the compressor 126 of the turbocharger 124 ordownstream of the air cooler 130.

As shown in FIGS. 2 and 3 , the conduit 123 has a peripheral wall, shownas sidewall 125, including a plurality of wall portions, shown as firstwall section 290, second wall section 292, third wall section 294, andfourth wall section 296. As shown in FIG. 3 , the first wall section 290defines an aperture, shown as fuel mixer aperture 297. In otherembodiments, one of the second wall section 292, the third wall section294, or the fourth wall section 296 defines the fuel mixer aperture 297.As shown in FIGS. 2 and 3 , (i) the fuel mixer aperture 297 receives thestem 242 of the fuel mixer 220 such that the nozzle end 248 of the stem242 is positioned within the conduit 123 and the valve end 250 of thestem 242 is positioned outside of the conduit 123 and (ii) the nozzle222 is coupled to the nozzle end 248 of the stem 242 and positionedwithin the conduit 123.

As shown in FIG. 3 , the seals 298 are positioned at opposing sides ofthe sidewall 125 and the fuel mixer aperture 297. The fasteners 300 arepositioned to (i) compress the seals 298 against the interface of thestem 242 and the fuel mixer aperture 297 to generate an air-tight sealbetween the stem 242 and the conduit 123 and (ii) couple or secure thestem 242 and, thereby, the fuel mixer 220 to the sidewall 125 of theconduit 123. In other embodiments, the fuel mixer 220 does not includethe seals 298 and/or the fasteners 300. By way of example, the stem 242may be adhesively secured within the fuel mixer aperture 297. By way ofanother example, the stem 242 may be welded to the sidewall 125 of theconduit 123. By way of yet another example, the conduit 123 and the stem242 may be an integral component having a unitary structure that isinserted into the air supply system 106.

According to an exemplary embodiment, the nozzle 222 is sized and shapedto have a streamlined physical profile such that a substantial majorityof the air flowing through the conduit 123 is substantially unobstructedby the physical presence of the fuel mixer 220 (e.g., the stem 242, thenozzle body 228 of the nozzle 222, etc.) within the conduit 123. As aresult, the volume and flow rate of the air available to the engine 104through the air supply system 106 may, therefore, be substantiallyunrestricted by the inclusion of the fuel mixer 220 within the airsupply system 106.

As shown in FIG. 3 , the nozzle 222 defines a first area, shown asnozzle flow area 302, and the conduit 123 defines a second area, shownas conduit area 304. According to the exemplary embodiment shown in FIG.3 , the nozzle flow area 302 is smaller than the conduit area 304.Therefore, all of the air flowing into and through the air supply system106 and the conduit 123 does not flow through nozzle passage 233 of thenozzle 222, but only a portion of the air flowing into and through theair supply system 106 flows through the nozzle passage 233 of the nozzle222. More specifically, as shown in FIG. 2 , a first portion 332 offiltered, inlet air 330 drawn into the air supply system 106 flows intothe nozzle passage 233 of the nozzle 222 and a second portion 334 of theinlet air 330 drawn into the air supply system 106 flows around andbypasses the nozzle passage 233 between an interior surface 127 of thesidewall 125 of the conduit 123 and the outer surface 229 of the nozzlebody 228 of the nozzle 222. Accordingly, as shown in FIG. 3 , a thirdarea, shown as bypass flow area 306, is defined between the interiorsurface 127 of the sidewall 125 of the conduit 123 and the outer surface229 of the nozzle body 228 of the nozzle 222 through which the secondportion 334 of the inlet air 330 flows. The conduit area 304 is,therefore, the combination of the nozzle flow area 302 and the bypassflow area 306

In an alternative embodiment, all of the inlet air 330 that is drawninto the air supply system 106 flows through the nozzle 222. By way ofexample, the nozzle 222 may be integrated as a section insert betweentwo adjacent conduit portions and have a diameter substantially equal tothe two conduit portions such that all of the inlet air 330 flowing intoand through the air supply system 106 flows though the nozzle passage233 of the nozzle 222.

Fuel Mixer Function

As shown in FIGS. 2 and 3 , (i) the inlet air 330 flows through the airintake 120, through the air cleaner 122, and into the conduit 123 withinwhich the nozzle 222 of the fuel mixer 220 is positioned, (ii) the firstportion 332 of the inlet air 330 flows through the nozzle 222, (iii) thesecond portion 334 of the inlet air 330 flows around the nozzle 222, and(iv) the first portion 332 and the second portion 334 rejoin downstreamof the nozzle 222 as downstream air 336. The downstream air 336 thenflows through the remainder of the air supply system 106 (e.g., thecompressor 126 of the turbocharger 124, the air cooler 130, etc.) and isprovided to the intake manifold 142 of the engine 104. When thesupplemental fuel system 200 is operational (e.g., the first electroniclock off 206 and the second electronic lock off 208 are open), asupplemental fuel supply, shown as supplemental fuel 338, may beprovided, injected, drawn, etc. into the nozzle passage 233 to dose ormix with the first portion 332 of the inlet air 330 flowing through thenozzle 222. The downstream air 336 may, therefore, either be the inletair 330 (e.g., when the supplemental fuel system 200 is not operational)or a mixture of inlet air 330 and the supplemental fuel 338 (e.g., whenthe supplemental fuel system 200 is operational).

According to an exemplary embodiment, when the supplemental fuel system200 is operational, the flow profile 280 of the nozzle 222 is configuredto provide a Venturi effect as the first portion 332 of the inlet air330 flows through the nozzle passage 233 of the nozzle 222 thatgenerates a vacuum signal at the nozzle end 248 of the stem 242 and,therefore, at the outlet of the low pressure regulator 210. The vacuumsignal causes the supplemental fuel 338 to be drawn from the lowpressure regulator 210, through the fuel flow valve 260, through thestem 242, and out of the supplemental fuel inlet 235 of the nozzle 222into the nozzle passage 233 of the nozzle 222 where the supplementalfuel 338 mixes with the first portion 332 of the inlet air 330, and themixture subsequently rejoins the second portion 334 of the inlet air 330to provide the downstream air 336.

More specifically, the structure and shape of inlet taper 237 at the airinlet 282 of the flow profile 280 is configured to increase pressure ofthe first portion 332 of the inlet air 330 entering the inlet end 230 ofthe nozzle 222. As the first portion 332 of the inlet air 330 flowsthrough the mixing chamber 284 and out of the mixture outlet 286 of theflow profile 280, the structure and shape of the mixing chamber 284 andthe outlet taper 239 at the mixture outlet 286 of the flow profile 280is configured to increase the velocity of the first portion 332 of theinlet air 330, thus reducing the pressure of the first portion 332 ofthe inlet air 330 flowing through the air inlet 282 of the flow profile280. The reduced pressure of the first portion 332 of the inlet air 330flowing through the mixing chamber 284 and out of the mixture outlet 286generates a vacuum across the supplemental fuel inlet 235 and,therefore, the vacuum signal at the outlet of the low pressure regulator210. According to an exemplary embodiment, the low pressure regulator210 is configured to release the supplemental fuel 338 to the fuel flowvalve 260 in response to and based on the vacuum signal.

According to an exemplary embodiment, a higher velocity or flow rate ofthe inlet air 330 and the downstream air 336 through the air supplysystem 106, and consequently through the nozzle 222, generates a greatervacuum signal in the supplemental fuel system 200 (i.e., at the lowpressure regulator 210). By way of example, the vacuum signal may beproportional to the velocity or flow rate of the inlet air 330 and thedownstream air 336. The velocity and flow rate of the inlet air 330 andthe downstream air 336 increases as the speed (i.e.,revolutions-per-minute (“rpms”)) of the engine 104 increases because, asthe speed of the engine 104 increases, more exhaust is output to theturbine 128 of the turbocharger 124, which ultimately drives thecompressor 126 of the turbocharger 124 faster and, therefore, draws moreand faster air into and through the air supply system 106. Therefore, asthe vacuum signal fluctuates (i.e., increases or decreases), the amountof the supplemental fuel 338 released by the low pressure regulator 210and provided to the fuel mixer 220 will similarly fluctuate. In thisway, the quantity of the supplemental fuel 338 entering the air supplysystem 106 is mechanically regulated by the fuel mixer and the regularoperation of the engine 104 and the turbocharger 124 (i.e., the airflowcaused thereby within the air supply system 106) without the use ofelectronic monitoring or electronic supplemental fueling supply control.

Advantageously, the mechanically regulated supply of the supplementalfuel 338 provided by the supplemental fuel system 200 may facilitate animprovement in the driveline 100 that consumes less liquid fuel (e.g.,diesel fuel) during the operation of the engine 104, may improve overallfuel efficiency of the engine 104, may reduce the generation ofpollutants, and/or may facilitate a reduced engine fuel cost of theengine 104. The supplemental fuel system 200 may further facilitate animproved installation process and usability. For example, a user of thesupplemental fuel system 200 may not need to interact with the ECU ofthe engine 104 or directly modify or monitor a control scheme of theprimary fuel system 102 to install and/or utilize the supplemental fuelsystem 200. Additionally, because the flow of gaseous fuel into the airsupply system 106 is regulated primarily in response to a low pressuresignal generated by regular operation of the driveline 100, the quantityof gaseous fuel entering the air supply system 106 is reactive to theoperational speed of the engine 104 without requiring a costly and/orcomplex electronic engine monitoring system. In other words, as more airis drawn into the air supply system 106 during higher engine speeds ofthe engine 104, a proportionate increase in the quantity of thesupplemental fuel 338 may be mechanically drawn into the air supplysystem 106 from the low pressure regulator 210 based on an increasedvacuum signal.

In some embodiments, when the engine 104 is off or idling (e.g., notconsuming fuel, not cycling, at idle speeds, etc.), a negligible orreduced amount of air flows through the air supply system 106, leadingto a negligible or insignificant vacuum signal being generated by thefuel mixer 220, which may at least partially cause one or morecomponents of the supplemental fuel system 200 (e.g., the low pressureregulator 210, the first electronic lock off 206, etc.) to block orprevent a flow of the supplemental fuel 338 from being provided to theair supply system 106.

In some embodiments, the fuel flow valve 260 is adjusted (e.g., opened,closed, fully opened, fully closed, etc.) to accommodate various airsupply systems 106 and/or engines 104 of a specific vehicle to which thesupplemental fuel system 200 is being used with. In some embodiments,the fuel flow valve 260 is adjustable to achieve a threshold engineperformance or threshold ratio of air to supplemental fuel (e.g.,gaseous fuel) to primary fuel (e.g., liquid fuel). In some embodiments,the fuel flow valve 260 of the fuel mixer 220 is adjusted (e.g., atleast partially closed) to alter the vacuum signal output from the fuelmixer 220.

In some embodiments, the engine 104 (e.g., via an ECU) may be configuredto reduce the amount of primary fuel (e.g., diesel fuel) used therebyduring an engine operation based on the amount of supplemental fuel 338added to the air flow by the supplemental fuel system 200 and providedto the engine 104 (e.g., reducing primary fuel consumption).

While the fuel mixer 220 has been disclosed herein as including aVenturi nozzle that facilitates mechanically and passively dosing theinlet air 330 with the supplemental fuel 338 based on the vacuum signal,in other implementations, the fuel mixer 220 may be replaced with anactively controlled fuel mixer (e.g., controlled by the supplementalfuel control system 350). By way of example, the fuel mixer 220 may bereplaced with a supplemental fuel injector that iselectrically-controllable to inject a suitable amount of thesupplemental fuel 338 into the conduit 123. By way of example, thesupplemental fuel injector may be controlled based on sensor inputsincluding engine speed, throttle position, velocity and/or flow rate ofthe inlet air 330 and/or the downstream air 336, an amount of boostbeing generated by the turbocharger 124, and/or other performanceparameters of the driveline 100.

Control System

As shown in FIGS. 1 and 9 , the supplemental fuel control system 350includes (i) a system controller, shown as controller 352, (ii) aplurality of sensors, shown as pressure sensor 360, voltage sensor 362,engine temperature sensor 364, and exhaust temperature sensor 366, and(iii) a user input/output device, shown as user interface 370. In someembodiments, the supplemental fuel control system 350 does not includethe user interface 370. In some embodiments, the supplemental fuelcontrol system 350 does not include one or more of the pressure sensor360, the voltage sensor 362, the engine temperature sensor 364, or theexhaust temperature sensor 366.

According to the exemplary embodiment shown in FIGS. 1 and 9 , thecontroller 352 is configured to selectively engage, selectivelydisengage, control, or otherwise communicate with components of thesupplemental fuel system 200 and the supplemental fuel control system350. By way of example, the controller 352 may send and receive signals(e.g., control signals, data, etc.) with the first electronic lock off206, the second electronic lock off 208, the pressure sensor 360, thevoltage sensor 362, the engine temperature sensor 364, the exhausttemperature sensor 366, and/or the user interface 370.

The controller 352 may be implemented as a general-purpose processor, anapplication specific integrated circuit (“ASIC”), one or more fieldprogrammable gate arrays (“FPGAs”), a digital-signal-processor (“DSP”),circuits containing one or more processing components, circuitry forsupporting a microprocessor, a group of processing components, or othersuitable electronic processing components. According to the exemplaryembodiment shown in FIG. 9 , the controller 352 includes a processingcircuit 354 having a processor 356 and a memory 358. The processingcircuit 354 may include an ASIC, one or more FPGAs, a DSP, circuitscontaining one or more processing components, circuitry for supporting amicroprocessor, a group of processing components, or other suitableelectronic processing components. In some embodiments, the processingcircuit 354 is configured to execute computer code stored in the memory358 to facilitate the activities described herein. The memory 358 may beany volatile or non-volatile computer-readable storage medium capable ofstoring data or computer code relating to the activities describedherein. According to an exemplary embodiment, the memory 358 includescomputer code modules (e.g., executable code, object code, source code,script code, machine code, etc.) configured for execution by theprocessing circuit 354. In some embodiments, the controller 352 mayrepresent a collection of processing devices (e.g., servers, datacenters, etc.). In such cases, the processing circuit 354 represents thecollective processors of the devices, and the memory 358 represents thecollective storage devices of the devices.

As shown in FIG. 1 , the pressure sensor 360 is positioned to acquirepressure data from the pressurized fuel tank 202 regarding a pressure ofthe supplemental fuel within the pressurized fuel tank 202. In someembodiments, the pressure sensor 360 is additionally or alternativelyconfigured to acquire pressure data regarding a pressure downstream ofthe pressurized fuel tank 202 (e.g., in a conduit). The pressure sensor360 may be in wired or wireless communication with the controller 352.As shown in FIG. 1 , the voltage sensor 362 is positioned to acquirevoltage data from the power supply 112 regarding a voltage of the powersupply 112. By way of example, the voltage sensor 362 may be positionedon a terminal of a battery of the power supply 112. The voltage sensor362 may be in wired or wireless communication with the controller 352.As shown in FIG. 1 , the engine temperature sensor 364 is positioned toacquire engine temperature data from the engine 104 regarding atemperature of the engine 104. By way of example, the engine temperaturesensor 364 may be positioned to measure the temperature of the engine104 through the water jacket of the engine 104. The engine temperaturesensor 364 may be in wired or wireless communication with the controller352. As shown in FIG. 1 , the exhaust temperature sensor 366 ispositioned to acquire exhaust temperature data from the exhaust manifold144 of the engine 104 and/or from the exhaust system 108 regarding atemperature of the exhaust flowing out of the engine 104 and through theexhaust system 108. By way of example, the exhaust temperature sensor366 may be positioned proximate the exhaust manifold 144. By way ofanother example, the exhaust temperature sensor 366 may be positionedupstream of the turbine 128 of the turbocharger 124. By way of stillanother example, the exhaust temperature sensor 366 may be positioneddownstream of the turbine 128 of the turbocharger 124. By way of yetanother example, the exhaust temperature sensor 366 may be positionedupstream of exhaust aftertreatment components of the exhaust 150. By wayof yet still another example, the exhaust temperature sensor 366 may bepositioned downstream of exhaust aftertreatment components of theexhaust 150. The exhaust temperature sensor 366 may be in wired orwireless communication with the controller 352. According to anexemplary embodiment, the controller 352 is configured to control one ormore components of the supplemental fuel system 200 (e.g., the firstelectronic lock off 206, the second electronic lock off 208, toauto-engage the supplemental fuel system 200, the auto-disengage thesupplemental fuel system, etc.) and/or the user interface 370 based onthe pressure data, the voltage data, the engine temperature data, and/orthe exhaust temperature data.

As shown in FIGS. 9 and 10 , the user interface 370 includes an outputdevice, shown as display 372, configured to output information and aninput device, shown as button 374, configured to receive an input from auser. The button 374 may be a switch, knob, dial, a touch sensitiveinterface, etc. configured to facilitate turning the supplemental fuelsystem 200 on or off. By way of example, a user may selectively interactwith the button 374 to send a signal to the controller 352 to open orclose the first electronic lock off 206 and/or the second electroniclock off 208 (i.e., effectively turning the supplemental fuel system 200on or off). In this way, a user may interact with the button 374 toselectively enable (e.g., unlock, open, etc.) or disable (e.g., close,lock, etc.) the supplemental fuel system 200 to start or stop providinga fuel flow of the supplement fuel to the engine 104. In otherembodiments, the first electronic lock off 206 and/or the secondelectronic lock off 208 include manual actuators that facilitatemanually opening and closing the first electronic lock off 206 and/orthe second electronic lock off 208 in the absence of an electronicsignal from the controller 352.

The display 372 may include one or more light emitting devices (e.g.,screens, light emitting diodes, lights, LCD screens, OLED screens, etc.)for communicating the information to the user. As shown in FIG. 10 , thedisplay 372 of the user interface 370 includes a digital or analogoutput device, shown as pressure gauge 376, a first indicator (e.g.,light emitting device or portion), shown as system power indicator 378,and a second indicator, shown as system status indicator 380. Thepressure gauge 376 is configured to show a pressure based on thepressure data acquired by the pressure sensor 360. The system powerindicator 378 is configured to display an indication that thesupplemental fuel system 200 and the supplemental fuel control system350 have power (e.g., properly connected to the power supply 112, basedon the voltage data acquired by the voltage sensor 362, the ignition ofthe vehicle 10 is keyed on, etc.). The system status indicator 380 isconfigured to display an indication that the supplemental fuel system200 is turned on (i.e., engaged) or turned off (i.e., disengaged) (e.g.,based on an input provided to the button 374 by the user, based onauto-engagement/disengagement based on various sensor readings, etc.).

Pressure Based Control

According to an exemplary embodiment, the controller 352 is configuredto control components of the supplemental fuel system 200 (e.g., thefirst electronic lock off 206, the second electronic lock off 208, etc.)and/or components of the supplemental fuel control system 350 (e.g., theuser interface 370) based on the pressure data. Specifically, thecontroller 352 is configured to acquire the pressure data from thepressure sensor 360 to facilitate monitoring the pressure of thesupplemental fuel within and/or exiting the pressurized fuel tank 202.In some embodiments, the controller 352 is configured to control thepressure gauge 376 based on the pressure data. In some embodiments, thecontroller 352 is configured to compare the pressure of the supplementalfuel within or exiting the pressurized fuel tank 202 to a pressurethreshold (e.g., a low fuel pressure threshold). In response to thepressure being less than the pressure threshold (e.g., such that thesupplemental fuel may no longer be usable), the controller 352 may beconfigured to control to the first electronic lock off 206 and/or thesecond electronic lock off 208 such that the first electronic lock off206 and/or the second electronic lock off 208 close and prevent thesupplemental fuel from flowing along the supplemental fuel system 200and into the air supply system 106, thereby disengaging or “turning off”the supplemental fuel system 200.

Voltage Based Control

According to an exemplary embodiment, the controller 352 is configuredto control components of the supplemental fuel system 200 (e.g., thefirst electronic lock off 206, the second electronic lock off 208, etc.)and/or components of the supplemental fuel control system 350 (e.g., theuser interface 370) based on the voltage data. Specifically, thecontroller 352 is configured to acquire the voltage data from thevoltage sensor 362 to facilitate monitoring the voltage of the powersupply 112. Specifically, the voltage of the power supply 112 will varybased on whether the engine 104 is off or on. As an example, the powersupply 112 may have a first or nominal voltage (e.g., about 12 volts)when the engine 104 is off. However, when the engine 104 is started andrunning, the alternator 110 is driven by the engine 104. The alternator110, as a result, provides power to the power supply 112 and the voltagethereof increases to a second or elevated voltage (e.g., greater than 12volts, between 12.8 and 14 volts, greater than 12.8 volts, about 14volts, etc.).

In some embodiments, the controller 352 is configured to control thesystem power indicator 378, the first electronic lock off 206, and/orthe second electronic lock off 208 based on the voltage data and/or auser input (e.g., provided via the button 374). In some embodiments, thecontroller 352 is configured to compare the voltage of the power supply112 to a voltage threshold (e.g., greater than 12 volts, greater than12.8 volts, etc.). In response to the voltage being less than thevoltage threshold, the controller 352 may be configured to (i) controlto the system power indicator 378 (i.e., turn it off) to indicate thatthe supplemental fuel system 200 is not powered on and/or (ii) controlto the first electronic lock off 206 and/or the second electronic lockoff 208 such that the first electronic lock off 206 and/or the secondelectronic lock off 208 close and prevent the supplemental fuel fromflowing along the supplemental fuel system 200 and into the air supplysystem 106, thereby disengaging or “turning off” the supplemental fuelsystem 200. However, in response to the voltage being greater than thevoltage threshold and/or in response to receiving a user input to turnon the supplemental fuel system 200 (e.g., via the user interface 370),the controller 352 may be configured to (i) control to the system powerindicator 378 (i.e., turn it on) to indicate that the supplemental fuelsystem 200 is powered on and/or (ii) control to the first electroniclock off 206 and/or the second electronic lock off 208 such that thefirst electronic lock off 206 and/or the second electronic lock off 208open and permit the supplemental fuel to flow along the supplementalfuel system 200 and into the air supply system 106, thereby engaging or“turning on” the supplemental fuel system 200.

Accordingly, the controller 352 may be configured to control engagementand disengagement of the supplemental fuel system 200 based on operationof the engine 104 by monitoring the voltage data and without directlyhaving to determine whether the engine 104 has actually been turned onor is running. Therefore, the controller 352 may be configured todisengage the supplemental fuel system 200 anytime the engine 104 is notrunning (e.g., the vehicle 10 was involved in an accident and the engine104 stops running, the ignition was keyed off, etc.) without actuallydirectly determining if the engine 104 is running or monitoring theignition position.

Referring now to FIG. 11 , a method 1000 for controlling thesupplemental fuel system 200 based on the voltage of the power supply112 is shown, according to an exemplary embodiment. At step 1010, thecontroller 352 is configured to monitor the voltage of the power supply112 (e.g., via the voltage data acquired from the voltage sensor 362).At step 1020, the controller 352 is configured to compare the voltage ofthe power supply 112 to a voltage threshold and determine whether thevoltage is less than the voltage threshold (i.e., indicating that theengine 104 is off). If yes (i.e., the voltage is less than the voltagethreshold), the controller 352 is configured to proceed to step 1030. Ifno (i.e., the voltage is greater than the voltage threshold), thecontroller 352 is configured to proceed to step 1040.

At step 1030, the controller 352 is configured to control the firstelectronic lock off 206 and/or the second electronic lock off 208 suchthat the first electronic lock off 206 and/or the second electronic lockoff 208 close and, thereby, disengage or turn off the supplemental fuelsystem 200. The controller 352 is then configured to return to step 1020and continue to monitor the voltage and compare the voltage to thevoltage threshold. However, while the controller 352 continues tomonitor the voltage and continues to determine that the voltage is lessthan the voltage threshold (i.e., the engine 104 is off), a user may keythe ignition of the vehicle 10 to an on or start position (step 1032),which will cause the engine 104 to be started and run (step 1034), whichwill cause the alternator 110 to provide power to the power supply 112,increasing the voltage of the power supply 112 above the voltagethreshold. In response, the controller 352 will determine no at Step1020 and proceed to step 1040.

At step 1040, the controller 352 is configured to control the firstelectronic lock off 206 and/or the second electronic lock off 208 suchthat the first electronic lock off 206 and/or the second electronic lockoff 208 open and, thereby, engage or turn on the supplemental fuelsystem 200. The controller 352 is then configured to return to step 1020and continue to monitor the voltage and compare the voltage to thevoltage threshold. However, while the controller 352 continues tomonitor the voltage and continues to determine that the voltage isgreater than the voltage threshold (i.e., the engine 104 is on), theuser may key the ignition of the vehicle 10 to an off position (step1042) such that the engine 104 turns off and stops or the vehicle 10 mayencounter an event that causes the engine 104 to otherwise shut off(e.g., damage to the engine 104, damage to the primary fuel system 102,etc.) (step 1044), which will cause the alternator 110 to stop providingpower to the power supply 112, decreasing the voltage of the powersupply 112 below the voltage threshold. In response, the controller 352will determine yes at Step 1020 and proceed to step 1030.

Exhaust Temperature Based Control

According to an exemplary embodiment, the controller 352 is configuredto control components of the supplemental fuel system 200 (e.g., thefirst electronic lock off 206, the second electronic lock off 208, etc.)and/or components of the supplemental fuel control system 350 (e.g., theuser interface 370) based on the exhaust temperature data. Specifically,the controller 352 is configured to acquire the exhaust temperature datafrom the exhaust temperature sensor 366 to facilitate monitoring thetemperature of the exhaust gases exiting the engine 104 (e.g., out ofthe exhaust manifold 144) and/or flowing through the exhaust system 108.During operation of the vehicle 10, the temperature of the exhaust gasesexiting the engine 104 and/or flowing though the exhaust system 108 mayfluctuate. In some instances, the temperature of the exhaust gases mayreach elevated levels (e.g., above 800° F., between 915° F. and 1000°F., etc.), which may indicate that the driveline 100 is about to performa regeneration cycle. The controller 352 may be configured to disengageor turn off the supplemental fuel system 200 during events of highexhaust temperatures to reduce the risk of any interference with afactory/OEM designed regeneration process.

In some embodiments, the controller 352 is configured to compare thetemperature of the exhaust gases to an exhaust temperature threshold(e.g., 800° F., 825° F., 850° F., 875° F., 900° F., 925° F., etc.). Inresponse to the exhaust temperature being less than the exhausttemperature threshold (e.g., indicating that a regeneration process isnot likely) and/or in response to receiving a user input to turn on thesupplemental fuel system 200 (e.g., via the user interface 370), thecontroller 352 may be configured to control to the first electronic lockoff 206 and/or the second electronic lock off 208 such that the firstelectronic lock off 206 and/or the second electronic lock off 208 openand permit the supplemental fuel to flow along the supplemental fuelsystem 200 and into the air supply system 106, thereby engaging or“turning on” the supplemental fuel system 200. However, in response tothe exhaust temperature being greater than the exhaust temperaturethreshold (e.g., indicating that the regeneration process is likely),the controller 352 may be configured to control to the first electroniclock off 206 and/or the second electronic lock off 208 such that thefirst electronic lock off 206 and/or the second electronic lock off 208close and prevent the supplemental fuel from flowing along thesupplemental fuel system 200 and into the air supply system 106, therebydisengaging or “turning off” the supplemental fuel system 200.

Referring now to FIG. 12 , a method 2000 for controlling thesupplemental fuel system 200 based on the temperature of exhaust gasesis shown, according to an exemplary embodiment. At step 2010, the engine104 is running and outputting exhaust gases to the exhaust system 108.At step 2020, the exhaust temperature sensor 366 is configured toacquire exhaust temperature data by measuring the temperature of theexhaust gases. In some embodiments, the temperature of the exhaust gasesis measured at a plurality of locations along the exhaust system 108 viaa plurality of exhaust temperature sensors 366. At step 2030, thecontroller 532 is configured to acquire the exhaust temperature data anddetermine/monitor an exhaust temperature of the exhaust gases. At step2040, the controller 352 is configured to compare the exhausttemperature to an exhaust temperature threshold. According to anexemplary embodiment, the exhaust temperature threshold may be a maximumtemperature threshold of about 800° F. In some embodiments, the exhausttemperature threshold may be a maximum threshold below 800° F. In otherembodiments, the exhaust temperature threshold may be a maximumthreshold above 800° F. In still other embodiments, the exhausttemperature threshold may be a threshold range defining a minimumthreshold and a maximum threshold.

At step 2050, the controller 532 is configured to determine whether theexhaust temperature is greater than the exhaust temperature threshold.If no (i.e., the exhaust temperature is less than the exhausttemperature threshold), the controller 532 is configured to proceed tostep 2060. If yes (i.e., the exhaust temperature is greater than theexhaust temperature threshold), the controller 532 is configured toproceed to step 2070. At step 2060, in response to the exhausttemperature being greater than the exhaust temperature threshold, thecontroller 532 is configured to control the first electronic lock off206 and/or the second electronic lock off 208 to stop the flow of thesupplemental fuel. At step 2070, in response to the exhaust temperaturebeing less than the exhaust temperature threshold, the controller 532 isconfigured to control the first electronic lock off 206 and/or thesecond electronic lock off 208 to permit the flow of the supplementfuel.

Engine Temperature Based Control

According to an exemplary embodiment, the controller 352 is configuredto control components of the supplemental fuel system 200 (e.g., thefirst electronic lock off 206, the second electronic lock off 208, etc.)and/or components of the supplemental fuel control system 350 (e.g., theuser interface 370) based on the engine temperature data. Specifically,the controller 352 is configured to acquire the engine temperature datafrom the engine temperature sensor 364 to facilitate monitoring thetemperature (e.g., the water jacket temperature) of the engine 104.During operation of the vehicle 10, the temperature of the the engine104 may fluctuate. By way of example, the engine 104 may be cold or notwarmed up after sitting for a period of time. By way of another example,the engine 104 may run hot or be overheating (e.g., when a regenerationcycle is occurring or is about to occur, when a cooling system fails,etc.). In such instances, it may be beneficial to stop supplying thesupplemental fuel to the engine 104 until the engine 104 returns to adesirable operating temperature range (e.g., between a minimumtemperature threshold and a maximum temperature threshold).

In some embodiments, the controller 352 is configured to compare thetemperature of the engine to an engine temperature threshold or atemperature range (e.g., between a minimum temperature threshold and amaximum temperature threshold). In response to the engine temperaturebeing less than the engine temperature threshold or outside of thetemperature range (e.g., indicating that the engine 104 is running hotor cold), the controller 352 may be configured to control to the firstelectronic lock off 206 and/or the second electronic lock off 208 suchthat the first electronic lock off 206 and/or the second electronic lockoff 208 close and prevent the supplemental fuel from flowing along thesupplemental fuel system 200 and into the air supply system 106, therebydisengaging or “turning off” the supplemental fuel system 200. However,in response to the engine temperature being greater than the enginetemperature threshold or inside of the temperature range (e.g.,indicating that the engine 104 is warmed up but not at an elevatedtemperature (a regeneration temperature) or overheating) and/or inresponse to receiving a user input to turn on the supplemental fuelsystem 200 (e.g., via the user interface 370), the controller 352 may beconfigured to control to the first electronic lock off 206 and/or thesecond electronic lock off 208 such that the first electronic lock off206 and/or the second electronic lock off 208 open and permit thesupplemental fuel to flow along the supplemental fuel system 200 andinto the air supply system 106, thereby engaging or “turning on” thesupplemental fuel system 200.

Referring now to FIG. 13 , a method 3000 for controlling thesupplemental fuel system 200 based on the temperature of the engine 104is shown, according to an exemplary embodiment. At step 3010, the engine104 is started. At step 3020, the engine temperature sensor 364 isconfigured to acquire engine temperature data by measuring thetemperature of the engine 104. In some embodiments, the enginetemperature is measured via a plurality of engine temperature sensors364. In some embodiments, the engine temperature is measured via a waterjacket temperature sensor for measuring a temperature of the waterjacket of the engine 104. At step 3030, the controller 352 is configuredto acquire the engine temperature data and determine/monitor the enginetemperature of the engine 104. At step 3040, the controller 352 isconfigured to compare the engine temperature to an engine temperaturethreshold. The engine temperature threshold may be a minimum temperaturethreshold. In some embodiments, the controller 352 is configured tocompare the engine temperature to an operating temperature range (e.g.,a range between the minimum temperature threshold and a maximumtemperature threshold). In such embodiments, a lower limit of theoperating temperature range may be substantially similar to the enginetemperature threshold.

At step 3050, the controller 532 is configured to determine whether theengine temperature is greater than the engine temperature threshold orwithin the operating temperature range. If yes (i.e., the enginetemperature is greater than the engine temperature threshold or withinthe operating temperature range), the controller 532 is configured toproceed to step 3060. If no (i.e., the engine temperature is less thanthe engine temperature threshold or outside of the operating temperaturerange), the controller 532 is configured to proceed to step 3070. Atstep 3060, in response to the engine temperature being greater than theengine temperature threshold or within the operating temperature range,the controller 352 is configured to control the first electronic lockoff 206 and/or the second electronic lock off 208 to permit the flow ofthe supplemental fuel. In step 3070, in response to the enginetemperature being below the engine temperature threshold or outside ofthe operating temperature range, the controller 352 is configured tocontrol the first electronic lock off 206 and/or the second electroniclock off 208 to prevent the flow of the supplement fuel.

As utilized herein with respect to numerical ranges, the terms“approximately,” “about,” “substantially,” and similar terms generallymean +/−10% of the disclosed values, unless specified otherwise. Asutilized herein with respect to structural features (e.g., to describeshape, size, orientation, direction, relative position, etc.), the terms“approximately,” “about,” “substantially,” and similar terms are meantto cover minor variations in structure that may result from, forexample, the manufacturing or assembly process and are intended to havea broad meaning in harmony with the common and accepted usage by thoseof ordinary skill in the art to which the subject matter of thisdisclosure pertains. Accordingly, these terms should be interpreted asindicating that insubstantial or inconsequential modifications oralterations of the subject matter described and claimed are consideredto be within the scope of the disclosure as recited in the appendedclaims.

The hardware and data processing components used to implement thevarious processes, operations, illustrative logics, logical blocks,modules and circuits described in connection with the embodimentsdisclosed herein may be implemented or performed with a general purposesingle- or multi-chip processor, a digital signal processor (DSP), anapplication specific integrated circuit (ASIC), a field programmablegate array (FPGA), or other programmable logic device, discrete gate ortransistor logic, discrete hardware components, or any combinationthereof designed to perform the functions described herein. A generalpurpose processor may be a microprocessor, or, any conventionalprocessor, controller, microcontroller, or state machine. A processoralso may be implemented as a combination of computing devices, such as acombination of a DSP and a microprocessor, a plurality ofmicroprocessors, one or more microprocessors in conjunction with a DSPcore, or any other such configuration. In some embodiments, particularprocesses and methods may be performed by circuitry that is specific toa given function. The memory (e.g., memory, memory unit, storage device)may include one or more devices (e.g., RAM, ROM, Flash memory, hard diskstorage) for storing data and/or computer code for completing orfacilitating the various processes, layers and modules described in thepresent disclosure. The memory may be or include volatile memory ornon-volatile memory, and may include database components, object codecomponents, script components, or any other type of informationstructure for supporting the various activities and informationstructures described in the present disclosure. According to anexemplary embodiment, the memory is communicably connected to theprocessor via a processing circuit and includes computer code forexecuting (e.g., by the processing circuit or the processor) the one ormore processes described herein.

The present disclosure contemplates methods, systems and programproducts on any machine-readable media for accomplishing variousoperations. The embodiments of the present disclosure may be implementedusing existing computer processors, or by a special purpose computerprocessor for an appropriate system, incorporated for this or anotherpurpose, or by a hardwired system. Embodiments within the scope of thepresent disclosure include program products comprising machine-readablemedia for carrying or having machine-executable instructions or datastructures stored thereon. Such machine-readable media can be anyavailable media that can be accessed by a general purpose or specialpurpose computer or other machine with a processor. By way of example,such machine-readable media can comprise RAM, ROM, EPROM, EEPROM, orother optical disk storage, magnetic disk storage or other magneticstorage devices, or any other medium which can be used to carry or storedesired program code in the form of machine-executable instructions ordata structures and which can be accessed by a general purpose orspecial purpose computer or other machine with a processor. Combinationsof the above are also included within the scope of machine-readablemedia. Machine-executable instructions include, for example,instructions and data which cause a general purpose computer, specialpurpose computer, or special purpose processing machines to perform acertain function or group of functions.

Although the figures and description may illustrate a specific order ofmethod steps, the order of such steps may differ from what is depictedand described, unless specified differently above. Also, two or moresteps may be performed concurrently or with partial concurrence, unlessspecified differently above. Such variation may depend, for example, onthe software and hardware systems chosen and on designer choice. Allsuch variations are within the scope of the disclosure. Likewise,software implementations of the described methods could be accomplishedwith standard programming techniques with rule-based logic and otherlogic to accomplish the various connection steps, processing steps,comparison steps, and decision steps.

It should be noted that the term “exemplary” and variations thereof, asused herein to describe various embodiments, are intended to indicatethat such embodiments are possible examples, representations, orillustrations of possible embodiments (and such terms are not intendedto connote that such embodiments are necessarily extraordinary orsuperlative examples).

The term “coupled” and variations thereof, as used herein, means thejoining of two members directly or indirectly to one another. Suchjoining may be stationary (e.g., permanent or fixed) or moveable (e.g.,removable or releasable). Such joining may be achieved with the twomembers coupled directly to each other, with the two members coupled toeach other using a separate intervening member and any additionalintermediate members coupled with one another, or with the two memberscoupled to each other using an intervening member that is integrallyformed as a single unitary body with one of the two members. If“coupled” or variations thereof are modified by an additional term(e.g., directly coupled), the generic definition of “coupled” providedabove is modified by the plain language meaning of the additional term(e.g., “directly coupled” means the joining of two members without anyseparate intervening member), resulting in a narrower definition thanthe generic definition of “coupled” provided above. Such coupling may bemechanical, electrical, or fluidic.

The term “or,” as used herein, is used in its inclusive sense (and notin its exclusive sense) so that when used to connect a list of elements,the term “or” means one, some, or all of the elements in the list.Conjunctive language such as the phrase “at least one of X, Y, and Z,”unless specifically stated otherwise, is understood to convey that anelement may be either X; Y; Z; X and Y; X and Z; Y and Z; or X, Y, and Z(i.e., any combination of X, Y, and Z). Thus, such conjunctive languageis not generally intended to imply that certain embodiments require atleast one of X, at least one of Y, and at least one of Z to each bepresent, unless otherwise indicated.

References herein to the positions of elements (e.g., “top,” “bottom,”“above,” “below”) are merely used to describe the orientation of variouselements in the FIGURES. It should be noted that the orientation ofvarious elements may differ according to other exemplary embodiments,and that such variations are intended to be encompassed by the presentdisclosure.

It is important to note that the construction and arrangement of thevehicle 10, the driveline 100, and the supplemental fuel system 200 andcomponents thereof as shown in the various exemplary embodiments isillustrative only. Additionally, any element disclosed in one embodimentmay be incorporated or utilized with any other embodiment disclosedherein.

The invention claimed is:
 1. A supplemental fuel system for a machinehaving a compression-ignition engine, the supplemental fuel systemcomprising: a supplemental fuel tank configured to store a supplementalfuel at a first pressure, the supplemental fuel configured to supplementa primary fuel used by the compression-ignition engine; a first pressureregulator configured to be positioned downstream of the supplementalfuel tank, the first pressure regulator configured to reduce the firstpressure of the supplemental fuel received from the supplemental fueltank to a second pressure; a second pressure regulator configured to bepositioned downstream of the first pressure regulator, the secondpressure regulator configured to reduce the second pressure of thesupplemental fuel received from the first pressure regulator to a thirdpressure; a nozzle configured to be positioned (i) downstream of thesecond pressure regulator and (ii) within a conduit of an air supplysystem for the compression-ignition engine, the nozzle configured toreceive a flow of the supplemental fuel and provide the supplementalfuel to air flowing though the conduit, wherein the nozzle has a bodydefining a first inlet positioned at a first nozzle end thereof, anoutlet positioned at an opposing second nozzle end thereof, a secondinlet positioned between the first nozzle end and the opposing secondnozzle end, and a nozzle passage extending from the first nozzle end tothe opposing second nozzle end that is configured to receive the airflowing through the conduit; a stem having a first stem end and a secondstem end, the first stem end interfacing with the second inlet, the stemconfigured to extend through a wall of the conduit such that the secondstem end is positioned outside of the conduit, the stem configured toreceive the flow of the supplemental fuel from the second pressureregulator and provide the flow of the supplemental fuel to the nozzlepassage of the nozzle through the second inlet; a pair of sealsconfigured to be positioned at opposing sides of an interface where thestem extends through the wall of the conduit; a pair of fastenersconfigured to compress the pair of seals against the interface toprovide an air-tight seal at the interface; an electronic lock off valveconfigured to be positioned between the supplemental fuel tank and thenozzle; and a controller configured to control the electronic lock offvalve to selectively disengage the supplemental fuel system and preventthe supplemental fuel from being provided to the air flowing through theconduit.
 2. The supplemental fuel system of claim 1, further comprisingthe conduit, wherein the conduit is an air intake tube.
 3. Thesupplemental fuel system of claim 1, wherein the nozzle is configured tobe positioned within the conduit between an air intake and aturbocharger of the air supply system.
 4. The supplemental fuel systemof claim 1, wherein the supplemental fuel tank is configured to storethe supplemental fuel as a compressed, gaseous fuel.
 5. The supplementalfuel system of claim 1, wherein the electronic lock off valve isconfigured to be positioned between the first pressure regulator and thesecond pressure regulator.
 6. The supplemental fuel system of claim 1,wherein the electronic lock off valve is a first electronic lock offvalve, further comprising a second electronic lock off valve configuredto be positioned downstream of the first electronic lock off valve andupstream of the nozzle.
 7. The supplemental fuel system of claim 1,further comprising a user interface configured to receive a user inputfrom an operator, wherein the controller is configured to control theelectronic lock off valve based on the user input.
 8. The supplementalfuel system of claim 7, wherein the controller is configured to controlthe user interface to provide an indication to the operator regarding anoperating characteristic of the supplemental fuel system.
 9. Thesupplemental fuel system of claim 1, further comprising a sensorconfigured to acquire data regarding operation of at least one of thesupplemental fuel system or the machine, wherein the controller isconfigured to control the electronic lock off valve to at least one ofautomatically engage or automatically disengage the supplemental fuelsystem based on the data.
 10. The supplemental fuel system of claim 1,wherein the nozzle has a first cross-sectional dimension that isconfigured to be less than a second cross-sectional dimension of theconduit such that only a portion of the air flowing through the conduitis configured to flow through the nozzle.
 11. The supplemental fuelsystem of claim 1, wherein the nozzle is a Venturi nozzle that isconfigured to generate a vacuum signal at the second pressure regulatoras the air flowing through the conduit flows through the nozzle, andwherein the nozzle is configured to receive a flow of the supplementalfuel from the second pressure regulator in response to and based on thevacuum signal.
 12. The supplemental fuel system of claim 1, wherein thenozzle passage has a non-uniform profile including a first transitionpoint, a second transition point, an inlet taper extending from thefirst nozzle end to the first transition point, a mixing chamberpositioned between the first transition point and the second transitionpoint, and an outlet taper extending from the second transition point tothe opposing second nozzle end, wherein the inlet taper is differentthan the outlet taper, and wherein the second inlet is positioned alongthe mixing chamber.
 13. The supplemental fuel system of claim 12,wherein the second inlet is positioned closer to the second transitionpoint than the first transition point.
 14. A supplemental fuel systemfor a machine having a compression-ignition engine, the supplementalfuel system comprising: a supplemental fuel tank configured to store asupplemental fuel at a first pressure, the supplemental fuel configuredto supplement a primary fuel used by the compression-ignition engine; afirst pressure regulator configured to be positioned downstream of thesupplemental fuel tank, the first pressure regulator configured toreduce the first pressure of the supplemental fuel received from thesupplemental fuel tank to a second pressure; a second pressure regulatorconfigured to be positioned downstream of the first pressure regulator,the second pressure regulator configured to reduce the second pressureof the supplemental fuel received from the first pressure regulator to athird pressure; a nozzle configured to be positioned (i) downstream ofthe second pressure regulator and (ii) within a conduit of an air supplysystem for the compression-ignition engine, the nozzle configured toreceive a flow of the supplemental fuel and provide the supplementalfuel to air flowing though the conduit, wherein the nozzle has a bodydefining a first inlet positioned at a first nozzle end thereof, anoutlet positioned at an opposing second nozzle end thereof, a secondinlet positioned between the first nozzle end and the opposing secondnozzle end, and a nozzle passage extending from the first nozzle end tothe opposing second nozzle end that is configured to receive the airflowing through the conduit, wherein the nozzle passage has anon-uniform profile including a first transition point, a secondtransition point, an inlet taper extending from the first nozzle end tothe first transition point, a mixing chamber positioned between thefirst transition point and the second transition point, and an outlettaper extending from the second transition point to the opposing secondnozzle end, wherein the inlet taper is different than the outlet taper,wherein the second inlet is positioned along the mixing chamber, whereinthe body has a first diameter of about 3 inches, the mixing chamber hasa second diameter of about 2 inches, the body has a first length ofabout 4 inches, the inlet taper has a second length of about 0.5 inches,the mixing chamber has a third length of about 2 inches, and the outlettaper has a fourth length of about 1.5 inches, an electronic lock offvalve configured to be positioned between the supplemental fuel tank andthe nozzle; and a controller configured to control the electronic lockoff valve to selectively disengage the supplemental fuel system andprevent the supplemental fuel from being provided to the air flowingthrough the conduit.